Glossary

Formatting option that allows you to enter mathematical text, such as superscripts, subscripts, and Greek characters.

4G is the fourth generation of cellular data standards. Like 3G, there is no single 4G technology. Instead, 4G an umbrella of technologies that conform to the requirements established by the International Telecommunications Union. All 4G devices must support a data transfer rate of at least 100 Mbps.

4G networks and devices were first available in the United States in 2009. Sprint was the first company to offer 4G service, followed by Verizon, AT&T, and T-Mobile.

(of a process). To undergo or cause *abnormal termination.

Microsoft Access, often abbreviated "MS Access," is a popular database application for Windows. Access allows users to create custom databases that store information in an organized structure. The program also provides a visual interface for creating custom forms, tables, and SQL queries. Data can be entered into an Access database using either visual forms or a basic spreadsheet interface. The information stored within an Access database can be browsed, searched, and accessed from other programs, including Web services.

Adware is free software that is supported by advertisements. Common adware programs are toolbars that sit on your desktop or work in conjunction with your Web browser. They include features like advanced searching of the Web or your hard drive and better organization of your bookmarks and shortcuts. Adware can also be more advanced programs such as games or utilities. They are free to use, but require you to watch advertisements as long as the programs are open. Since the ads often allow you to click to a Web site, adware typically requires an active Internet connection to run.

An algorithm is a set of instructions, sometimes called a procedure or a function, that is used to perform a certain task. This can be a simple process, such as adding two numbers together, or a complex function, such as adding effects to an image. For example, in order to sharpen a digital photo, the algorithm would need to process each pixel in the image and determine which ones to change and how much to change them in order to make the image look sharper.

Android is Google's mobile operating system (OS) that is used by several smartphones, such as the G1, Droid, and Nexus One. Android is open source, meaning it is not linked to a specific cell phone manufacturer or service provider. The Android OS also supports third-party applications, which can be downloaded from Android Market, Google's online software store.

Stands for "American National Standards Institute." ANSI's primary goal is to enhance the global competitiveness of U.S. businesses and to improve the American quality of life by promoting and facilitating voluntary consensus standards and conformity assessment systems. "Voluntary" standards are driven by marketplace needs rather than regulated by the government. "Conformity assessment systems" test the compliance of a product or service to a standard. ANSI does not itself develop standards or conduct tests, rather it facilitates this work by "accrediting" (i.e., recognizing) qualified groups with appropriate expertise. The Institute is the official U.S. representative to the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). ANSI is a private, nonprofit membership organization with offices in Washington, DC and New York City.

Antivirus (also written "anti-virus" or simply "AV") is software designed to prevent, detect, and remove viruses from a computer. Once installed, most antivirus programs run in the background, scanning new files for viruses and performing regular system checks. You can also use an antivirus utility to scan individual files or folders directly. The software operates by checking files against a database of virus definitions, which contain signatures of known viruses. If a file contains a virus, the antivirus program will typically quarantine the file, making it inaccessible (and therefore removing the threat). It may also mark the file for deletion.

While antivirus software primarily scans for viruses, most modern antivirus programs also scan for other types of malware. This includes trojan horses, worms, spyware, and adware. Many antivirus programs are now included as part of "internet security" suites, which offer additional types of system protection, such as customizable firewalls, website blocking, and port monitoring.

Stands for "Application Program Interface," though it is sometimes referred to as an "Application Programming Interface." An API is a set of commands, functions, and protocols which programmers can use when building software for a specific operating system. The API allows programmers to use predefined functions to interact with the operating system, instead of writing them from scratch.

All computer operating systems, such as Windows, Unix, and the Mac OS, provide an application program interface for programmers. APIs are also used by video game consoles and other hardware devices that can run software programs. While the API makes the programmer's job easier, it also benefits the end user, since it ensures all programs using the same API will have a similar user interface.

Apple is the company that makes Macintosh computers, such as the iMac, Mac mini, MacBook, MacBook Air, MacBook Pro, and Mac Pro. Apple also makes several personal electronic devices, including the iPod, iPhone, and iPad.

While Apple is most known for its hardware devices, the company also develops a wide range of software. Examples include the Mac OS X operating system, iLife, iWork, and several professional media applications, such as Aperture, Logic Studio, and Final Cut Studio.

Apple has also expanded its reach online with the iTunes Store, App Store, and the new Mac App Store. These services allow you to download media and applications directly to your computer. Apple also has over 300 retail stores worldwide, which offer Apple products and provide Apple product support.

This a Java program that can be embedded in a Web page. The difference between a standard Java application and a Java applet is that an applet can't access system resources on the local computer. System files and serial devices (modems, printers, scanners, etc.) cannot be called or used by the applet. This is for security reasons -- nobody wants their system wiped out by a malicious applet on some wacko's Web site. Applets have helped make the Web more dynamic and entertaining and have given a helpful boost to the Java programming language.

An application, or application program, is a software program that runs on your computer. Web browsers, e-mail programs, word processors, games, and utilities are all applications.

The word "application" is used because each program has a specific application for the user. For example, a word processor can help a student create a research paper, while a video game can prevent the student from getting the paper done.

In contrast, system software consists of programs that run in the background, enabling applications to run. These programs include assemblers, compilers, file management tools, and the operating system itself. Applications are said to run on top of the system software, since the system software is made of of "low-level" programs. While system software is automatically installed with the operating system, you can choose which applications you want to install and run on your computer.

Macintosh programs are typically called applications, while Windows programs are often referred to as executable files. This is why Mac programs use the .APP file extension, while Windows programs use the .EXE extension. Though they have different file extensions, Macintosh and Windows programs serve the same purpose and can both be called applications.

An archive contains multiple files and/or folders within a single file. Archives can be saved in several different formats, most of which incorporate file compression to reduce the file size. They are used for consolidating a group of files into a single package. This can be helpful when transferring multiple files to another user or when backing up data.

In order to open the files contained in an archive, they must first be extracted using a file extraction utility. If the archive is compressed, it must be decompressed before the files can be extracted. Most file decompression programs perform both of these operations automatically.

An array is a data structure that contains a group of elements. Typically these elements are all of the same data type, such as an integer or string. Arrays are commonly used in computer programs to organize data so that a related set of values can be easily sorted or searched.

Stands for "American Standard Code for Information Interchange." ASCII is the universal standard for the numerical codes computers use to represent all upper and lower-case letters, numbers, and punctuation. Without ASCII, each type of computer would use a different way of representing letters and numbers, causing major chaos for computer programmers (allowing them even less sleep than they already get).

ASCII makes is possible for text to be represented the same way on a Dell Dimension in Minneapolis, Minnesota as it is on an Apple Power Mac in Paris, France. There are 128 standard ASCII codes, each of which can be represented by a 7 digit binary number (because 2^7 = 128).

A backup is a copy of one or more files created as an alternate in case the original data is lost or becomes unusable. For example, you may save several copies of a research paper on your hard drive as backup files in case you decide to use a previous revision. Better yet, you could save the backups to a USB flash disk, which would also protect the files if the hard drive failed.

Hard drives are meant to run for many years without crashing. But just like all electronic devices, they are not immune to problems. Because they are not solid state devices, hard drives rely on moving parts to access data, which can malfunction and cause your data to become unrecoverable. If you need proof of how fragile hard drives really are, go to your local computer store and have someone show you an open hard drive. When you realize all your data is stored in such a small, delicate device, you may have a new understanding of why you need to backup your data.

But it's not just hardware malfunctions you have to worry about. Software corruption can also damage your files. Directory structures can become damaged and cause entire folders to disappear. Files can be mistakenly deleted or corrupted by viruses or other software attacks. Program installation conflicts can make applications or files unusable. There are unfortunately many ways for your data to become damaged or disappear.

Stands for "Beginner's All-purpose Symbolic Instruction Code." BASIC is a computer programming language that was developed in the mid-1960s to provide a way for students to write simple computer programs. Since then, the language has evolved into a more robust and powerful language and can be used to create advanced programs for today's computer systems.

BASIC originally used numbers at the beginning of each instruction (or line) to tell the computer what order to process the instructions. Lines would be numbered as 10, 20, 30, etc., which would allow additional instructions to be placed between commands later on if needed. "GOTO" statements enabled programs to loop back to earlier instructions during execution. For example, line 230 of a BASIC program may have an "if" clause that tells the computer to jump back to line 50 if a variable is less than 10. This instruction might look something like this:

230 IF (N < 10) THEN GOTO 50

More modern BASIC implementations use "while loops," which perform a series of instructions as long as a certain case is true. Newer BASIC development software also supports more data types, such as integers, strings, and arrays, for storing variables and other data. While the first BASIC development environments were strictly text-based, today's BASIC programming software allows developers to design much of their programs visually, using a graphical user interface. Some of the more popular BASIC development programs used today include REALbasic and Microsoft Visual Basic.

A batch file is a type of script that contains a list of commands. These commands are executed in sequence and can be used to automate processes. For example, some programs may include a batch file that executes a number of commands as the program starts up. A user can also create a custom batch file to automate tedious processes such as copying multiple directories or renaming several files at once.

Batch files are run by the COMMAND.COM program, which is part of DOS and Windows. Therefore, batch files can only be run within the Windows operating system. Macintosh and Unix have other scripting tools, such as AppleScript and Unix shell commands, that can be used for similar tasks. Because batch files contain executable commands, it is important not to open unknown batch files on your hard disk or in e-mail attachments.

File Extensions: .BAT, .CMD

Binary is a two-digit (Base-2) numerical system, which computers use to store data and compute functions. The reason computers use the binary system is because digital switches inside the computer can only be set to either on or off, which are represented by a 1 or 0. Though the binary system consists of only ones and zeros, the two digits can be used to represent any number.

For example:

A single 0 in binary represents zero.
A single 1 represents (2^0) or 1.
10 represents (2^1) or 2.
11 represents (2^1 + 2^0) or 3.
100 represents (2^2) or 4.
101 represents (2^2 + 2^0) or 5.
110 represents (2^2 + 2^1) or 6.
111 represents (2^2 + 2^1 + 2^0) or 7.
1000 represents (2^3) or 8, and so on. 

Stands for "Basic Input/Output System." Most people don't need to ever mess with the BIOS on a computer, but it can be helpful to know what it is. The BIOS is a program pre-installed on Windows-based computers (not on Macs) that the computer uses to start up. The CPU accesses the BIOS even before the operating system is loaded. The BIOS then checks all your hardware connections and locates all your devices. If everything is OK, the BIOS loads the operating system into the computer's memory and finishes the boot-up process.

Since the BIOS manages the hard drives, it can't reside on one, and since it is available before the computer boots up, it can't live in the RAM. So where can this amazing, yet elusive BIOS be found? It is actually located in the ROM (Read-Only Memory) of the computer. More specifically, it resides in an eraseable programmable read-only memory (EPROM) chip. So, as soon as you turn your computer on, the CPU accesses the EPROM and gives control to the BIOS.

The BIOS also is used after the computer has booted up. It acts as an intermediary between the CPU and the I/O (input/output) devices. Because of the BIOS, your programs and your operating system don't have to know exact details (like hardware addresses) about the I/O devices attached to your PC. When device details change, only the BIOS needs to be updated. You can make these changes by entering the BIOS when your system starts up. To access the BIOS, hold down the DELETE or F2 key as soon as your computer begins to start up.

The smallest piece of computer information, either the number 0 or 1.

The computer term "bit" comes from the phrase "Binary DigIT," which is different than that thing you put around a horse's mouth. A bit is a single digit number in base-2 (a zero or a one) and is the smallest unit of computer data. A full page of text is composed of about 16,000 bits.

It is important not to confuse bits with bytes. Both are used to measure amounts of data, but it takes eight bits to make one byte. The most common area where bits are used intstead of bytes is in measuring bandwidth (in bits per second). Why? Probably because it makes your Internet connection sound faster than it really is.

Bitrate, as the name implies, describes the rate at which bits are transferred from one location to another. In other words, it measures how much data is transmitted in a given amount of time. Bitrate is commonly measured in bits per second (bps), kilobits per second (Kbps), or megabits per second (Mbps). For example, a DSL connection may be able to download data at 768 kbps, while a Firewire 800 connection can transfer data up to 800 Mbps.

Bitrate can also describe the quality of an audio or video file. For example, an MP3 audio file that is compressed at 192 Kbps will have a greater dynamic range and may sound slightly more clear than the same audio file compressed at 128 Kbps. This is because more bits are used to represent the audio data for each second of playback. Similarly, a video file that is compressed at 3000 Kbps will look better than the same file compressed at 1000 Kbps. Just like the quality of an image is measured in resolution, the quality of an audio or video file is measured by the bitrate.

BitTorrent is a peer-to-peer (P2P) file sharing protocol designed to reduce the bandwidth required to transfer files. It does this by distributing file transfers across multiple systems, thereby lessening the average bandwidth used by each computer. For example, if a user begins downloading a movie file, the BitTorrent system will locate multiple computers with the same file and begin downloading the file from several computers at once. Since most ISPs offer much faster download speeds than upload speeds, downloading from multiple computers can significantly increase the file transfer rate.

In order to use the BitTorrent protocol, you need a BitTorrent client, which is a software program that accesses the BitTorrent network. The client program allows you to search for files and begin downloading torrents, which are in-progress downloads. Most BitTorrent clients allow you to resume torrents that have been paused or stopped. This can be especially helpful when downloading large files.

For a list of BitTorrent clients, view the .TORRENT file extension entry.

Short for "Web Log," this term refers to a list of journal entries posted on a Web page. Anybody who knows how to create and publish a Web page can publish their own blog. Some Web hosts have made it even easier by creating an interface where users can simply type a text entry and hit "publish" to publish their blog.

Because of the simplicity of creating a blog, many people (often young kids and adults) have found a new presence on the Web. Instead of writing confidential entries in a book that no one is supposed to see, people now can share their personal feelings and experiences with thousands of people around the world. Blogs are typically updated daily, monthly, or anywhere in between. "Blog" may also be used as a verb, as in "Wow, Matt sure blogged a lot last week."

Blu-ray is an optical disc format such as CD and DVD. It was developed for recording and playing back high-definition (HD) video and for storing large amounts of data. While a CD can hold 700 MB of data and a basic DVD can hold 4.7 GB of data, a single Blu-ray disc can hold up to 25 GB of data. Even a double sided, dual layer DVD (which are not common) can only hold 17 GB of data. Dual-layer Blu-ray discs will be able to store 50 GB of data. That is equivalent to 4 hours of HDTV.

Blu-ray discs can hold more information than other optical media because of the blue lasers the drives use. The laser is actually blue-violet, but "Blu-ray" rolls off the tounge a little easier than "Blu-violet-ray." The blue-violet laser has a shorter wavelength than the red lasers used for CDs and DVDs (405nm compared to 650nm). This allows the laser to focus on a smaller area, which makes it possible to cram significantly more data on a disc the same size as a CD or DVD. Proponents of the Blu-ray format say they expect Blu-ray devices to replace VCRs (thank goodness) and DVD recorders as more people make the transition to HDTV. For the latest Blu-ray news, check out Blu-ray.com.

This wireless technology enables communication between Bluetooth-compatible devices. It is used for short-range connections between desktop and laptop computers, PDAs (like the Palm Pilot or Handspring Visor), digital cameras, scanners, cellular phones, and printers.

Infrared once served the same purpose as Bluetooth, but it had a number of drawbacks. For example, if there was an object placed between the two communicating devices, the transmission would be interrupted. (You may have noticed this limitation when using a television remote control). Also, the Infrared-based communication was slow and devices were often incompatible with each other.

Bluetooth takes care of all these limitations. Because the technology is based on radio waves, there can be objects or even walls placed between the communicating devices and the connection won't be disrupted. Also, Bluetooth uses a standard 2.4 GHz frequency so that all Bluetooth-enabled devices will be compatible with each other. The only drawback of Bluetooth is that, because of its high frequency, its range is limited to 30 feet. While this is easily enough for transferring data within the same room, if you are walking in your back yard and want to transfer the address book from your cell phone to your computer in your basement, you might be out of luck. However, the short range can be seen as a positive aspect as well, since it adds to the security of Bluetooth communication.

Short for "Bitmap." It can be pronounced as "bump," "B-M-P," or simply a "bitmap image." The BMP format is a commonly used raster graphic format for saving image files. It was introduced on the Windows platform, but is now recognized by many programs on both Macs and PCs.

The BMP format stores color data for each pixel in the image without any compression. For example, a 10x10 pixel BMP image will include color data for 100 pixels. This method of storing image information allows for crisp, high-quality graphics, but also produces large file sizes. The JPEG and GIF formats are also bitmaps, but use image compression algorithms that can significantly decrease their file size. For this reason, JPEG and GIF images are used on the Web, while BMP images are often used for printable images.

File Extension: .BMP

This is the logic that computers use to determine if a statement is true or false. There are 4 main boolean operators: AND, NOT, OR, and XOR. Below are some examples of how the 4 operators work:

x AND y returns True if both x and y are true, otherwise the expression returns False.

NOT x returns True if x is false (or null) and False if x is true.

x OR y returns True if either x or y or both are true; only if they are both false will it return False.

x XOR y returns True if either x or y are true, but not both. If x and y are both true or false, the statement will return False.

While boolean expressions are what drive the CPUs in computers, they can also be used by computer users. For example, when searching for information on the Web, many search engines accept boolean operators in the search phrases (i.e. "Yamaha AND piano NOT motorcycle"). Programmers often use boolean expressions in software development to control loops and variables as well.

When you boot a football, you kick it really far. When you boot a computer, you simply turn it on. Kicking your computer really far is not recommended, though you may be tempted to do so at times. The term "boot" comes from the word "bootstraps," which people at one time used to get their boots on. Likewise, "booting" a computer gets it up and running.

In simple terms, to boot a computer is to turn it on. Once the computer's power is turned on, the "boot process" takes place. This process involves loading the startup instructions from the computer's ROM, followed by loading the operating system from the current boot disk. The boot disk is usually an internal hard drive, but can also be an external drive, a CD or DVD-ROM, or even a floppy disk. Once the operating system software is loaded, the boot process is complete and the computer is ready to be used.

This is an automated software program that can execute certain commands when it receives a specific input (like a ro-"bot"). Bots are most often seen at work in the Internet-related areas of online chat and Web searching. The online chat bots do things like greet people when they enter a chat room, advertise Web sites, and kick people out of chat rooms when they violate the chat room rules. Web searching bots, also known as spiders and crawlers, search the Web and retrieve millions of HTML documents, then record the information and links found on the pages. From there, they generate electronic catalogs of the sites that have been "spidered." These catalogs make up the index of sites that are used for search engine results.

Stands for "Bits Per Second." (The "b" is lowercase because it stands for bits, not bytes.) Bits per second is the standard way of measuring how fast data moves across a network or phone system. For example, a 56K modem can hypothetically transfer data at 56,700 bits per second.

Software used to navigate the Internet.

Google Chrome, Firefox, Netscape Navigator and Microsoft Internet Explorer are today's most popular browsers for accessing the World Wide Web.

A malfunction due to an error in the program or a defect in the equipment.

Byte

C is a high-level programming language that was developed in the mid-1970s. It was originally used for writing Unix programs, but is now used to write applications for nearly every available platform. Compared to most previous languages, C is easier to read, more flexible (can be used for a wide variety of purposes), and more efficient at using memory.

C++, pronounced "C plus plus," is a programming language that was built off the C language. The syntax of C++ is nearly identical to C, but it has object-oriented features, which allow the programmer to create objects within the code. This makes programming easier, more efficient, and some would even say, more fun. Because of the power and flexibility of the language, most software programs today are written in C++.

Stands for "Computer-Aided Design." Also known by engineers and architects as the best invention of all time. Today, CAD software is used for nearly all three-dimensional designing. Designers can turn an object into an electronic representation more quickly and accurately than by diagraming it with a pencil and paper. Better yet, objects created with CAD software can be moved, resized, and rotated instantly. With a pencil and paper, you can only erase so much before it starts to smudge.

Caps lock is a feature nearly all keyboards have that, when active, capitalizes each letter typed on the keyboard. Unlike most keys on the keyboard, the caps lock key is a "toggle key," which is always in either an on or off position. When off, the letters typed are input like usual. When on, each letter typed is transmitted as an upper-case character. Caps lock does not alter the input from the rest of the keys, such as numbers and symbols.

Because caps lock changes the input of the letters on the keyboard, it is important to know whether it is on or off. Therefore, most keyboards have a light on the caps lock key that turns on when active, indicating caps lock is on. Because passwords are often case-sensitive, it is smart to make sure caps lock is not active when entering login information. Also, it is best not to use caps lock when typing e-mails because IT MAKES IT SEEM LIKE YOU ARE YELLING when you type in all caps.

"Card reader" is the generic term for an input device that reads flash memory cards. It can be a standalone device that connects to a computer via USB or it may be integrated into a computer, printer, or multifunction device. In fact, most multifunction printer/scanner/copiers now have built-in card readers.

Most card readers accept multiple memory card formats, including compact flash (CF), secure digital (SD), and Sony's Memory Stick. Some card readers accept various other formats such as XD, SmartMedia, Microdrive, and Memory Stick Pro Duo cards.

Stands for "Compact Disc." CDs are circular discs that are 4.75 in (12 cm) in diameter. The CD standard was proposed by Sony and Philips in 1980 and the technology was introduced to the U.S. market in 1983. CDs can hold up to 700 MB of data or 80 minutes of audio. The data on a CD is stored as small notches on the disc and is read by a laser from an optical drive. The drives translate the notches (which represent 1's and 0's) into usable data.

The first CDs were audio CDs, which eventually replaced audio tapes (which earlier replaced records). Audio CDs have the advantage of allowing the user to jump to different places on the disc. CDs can also be listened to an unlimited number of times without losing quality. Audio tapes can start to lose quality after listening to them as few as ten times. This is because the laser that reads the data on a CD doesn't put pressure on the disc, whereas the playheads on a tape deck slowly wear away the magnetic strip on the tape.

In 1985, CD-ROMs hit the computer market. Because they could store far more information than floppy discs (700 MB compared to 1.4 MB), CDs soon became the most common software format. In 1988, the CD-R (CD-Recordable) technology was introduced, allowing computer users to burn their own CDs. However, this technology did not become mainstream until the late 1990s. A smaller 3" CD, called "CD-3" is also available and is readable by most tray-loading CD-ROM drives.

Stands for "Compact Disc Recordable." CD-R discs are blank CDs that can record data written by a CD burner. The word "recordable" is used because CD-Rs are often used to record audio, which can be played back by most CD players. However, many other kinds of data can also be written to a CD-R, so the discs are also referred to as "writable CDs."

The data burned onto a CD-R disc is permanent, meaning it can not be altered or erased like the data on a hard drive. Typically, once a CD has been burned, it will not be able to record any more data. Some CD burning programs can record data as "sessions," allowing a disc to be written to mulitple times until it is full. Each session creates a new partition on the disc, meaning a computer will read a disc with multiple sessions as multiple discs. CD-RWs, on the other hand, can be erased and completely re-recorded. Like CDs, the data on CD-RWs cannot be altered, meaning the disc has to be completely erased each time you want to add new data.

Stands for "Compact Disc Read-Only Memory." A CD-ROM is a CD that can be read by a computer with an optical drive. The "ROM" part of the term means the data on the disc is "read-only," or cannot be altered or erased. Because of this feature and their large capacity, CD-ROMs are a great media format for retail software. The first CD-ROMs could hold about 600 MB of data, but now they can hold up to 700 MB. CD-ROMs share the same technology as audio CDs, but they are formatted differently, allowing them to store many types of data.

Stands for "Compact Disc Re-Writable." A CD-RW is a blank CD that can be written to by a CD burner. Unlike a CD-R (CD-Recordable), a CD-RW can be written to multiple times. The data burned on a CD-RW cannot be changed, but it can be erased. Therefore, you have to completely erase a CD-RW every time you want to change the files or add new data. While it may be somewhat inconvenient, this capability makes CD-RWs a good choice for making frequent backups. However, because CD-RWs can be erased, they don't store data reliably for as long as CD-Rs do. Therefore, you should use regular CD-Rs for long-term backups.

A character is any letter, number, space, punctuation mark, or symbol that can be typed on a computer. The word "computer," for example, consists of eight characters. The phrase "Hi there." takes up nine characters. Each character requires one byte of space, so "computer" takes up 8 bytes. The list of characters that can be typed is defined by the ASCII and extended ASCII set. Some of the symbols available are pretty strange and may even make you say, "That's quite a character!"

Technically speaking, a computer chip is a piece of silicon with an electronic circuit embedded in it. However, the word "chip" is often used as a slang term that refers to various components inside a computer. It typically describes an integrated circuit, or IC, such as a central processor or a graphics chip, but may also refer to other components such as a memory module.

While "chip" is a somewhat ambiguous term, it should not be confused with the term "card." For example, a laptop might have a graphics chip embedded in the motherboard, while a desktop computer may contain a graphics card connected to a PCI or AGP slot. A graphics card may contain a chip, but the chip cannot contain a card. Similarly, a CPU may contain a chip (the processor), but it may also contain several other components. Therefore, the term "chip" can be used to refer to specific components, but should not be used describe multiple components that are grouped together.

Stands for "Cyan Magenta Yellow Black." These are the four basic colors used for printing color images. Unlike RGB (red, green, blue), which is used for creating images on your computer screen, CMYK colors are "subtractive." This means the colors get darker as you blend them together. Since RGB colors are used for light, not pigments, the colors grow brighter as you blend them or increase their intensity.

Technically, adding equal amounts of pure cyan, magenta, and yellow should produce black. However, because of impurities in the inks, true black is difficult to create by blending the colors together. This is why black (K) ink is typically included with the three other colors. The letter "K" is used to avoid confusion with blue in RGB.

Computer software comes in three different flavors: freeware, shareware, and commercial software. Freeware is free to use and does not require any payment from the user. Shareware is also free to use, but typically limits the program's features or the amount of time the software can be used unless the user purchases the software. Commercial software requires payment before it can be used, but includes all the program's features, with no restrictions or time limits.

Commercial software programs typically come in a physical box, which is what you see displayed in retail stores. While it's true that the software boxes are not as big as they used to be, they still contain the software CD or DVD and usually a "getting started" manual along with a registration key used for registering the product. Most commercial software programs ask that the user register the program so the company can keep track of its authorized users. Some commercial software programs, such as newer versions of Microsoft and Adobe programs, require the user to register the programs in order to continue using them after 30 days.

While most commercial software programs are sold in the physical box, many software titles are now available as downloads. These downloads are typically made available from the company's website. The user pays for the program directly on the website and instead of receiving the software in the mail, the user downloads it to his computer. Another popular way of purchasing commercial software online is simply paying for a registration key, which unlocks the features of a shareware program. This upgrades the shareware program to the commercial version, which removes any feature limitations from the shareware version.

When programmers create software programs, they first write the program in source code, which is written in a specific programming language, such as C or Java. These source code files are saved in a text-based, human-readable format, which can be opened and edited by programmers. However, the source code cannot be run directly by the computer. In order for the code to be recognized by the computer's CPU, it must be converted from source code (a high-level language) into machine code (a low-level language). This process is referred to as "compiling" the code.

Most software development programs include a compiler, which translates source code files into machine code or object code. Since this code can be executed directly by the computer's processor, the resulting application is often referred to as an executable file. Windows executable files have a .EXE file extension, while Mac OS X programs have an .APP extension, which is often hidden.

Technically, a computer is a programmable machine. This means it can execute a programmed list of instructions and respond to new instructions that it is given. Today, however, the term is most often used to refer to the desktop and laptop computers that most people use. When referring to a desktop model, the term "computer" technically only refers to the computer itself -- not the monitor, keyboard, and mouse. Still, it is acceptable to refer to everything together as the computer. If you want to be really technical, the box that holds the computer is called the "system unit."

Some of the major parts of a personal computer (or PC) include the motherboard, CPU, memory (or RAM), hard drive, and video card. While personal computers are by far the most common type of computers today, there are several other types of computers. For example, a "minicomputer" is a powerful computer that can support many users at once. A "mainframe" is a large, high-powered computer that can perform billions of calculations from multiple sources at one time. Finally, a "supercomputer" is a machine that can process billions of instructions a second and is used to calculate extremely complex calculations.

A contextual menu is a pop-up menu that appears when you right-click on a certain area of the screen. It is "contextual" because the menu options are relevant to what you click on. While not all programs support contextual menus, most modern operating systems and applications include them as part of the interface design.

Contextual menus provide a choice of options that depend on where the cursor is when you click the right mouse button. For example, if you right-click on your computer's desktop, the menu that appears will have desktop-specific commands. These may include options to change the desktop background, create a new folder, clean up the icons, or view the desktop properties. If you right-click within a desktop window, you might see options to create a new folder, change the view options, or view the folder properties.

Right-clicking within an application typically provides menu options that are specific to the current program. For example, if you right-click in a Web browser window, the menu that appears may include options such as "Back," "Reload," and "Print." Right-clicking a misspelled word in a word processing program often presents a list of similar correctly spelled words. If you right-click a picture in an image-editing program, you may see a choice of editing options. These are just a few examples of the many contextual menus included in different programs.

It may be helpful to think of a contextual menu of as a streamlined menu bar. This is because they typically contain many of the same options as the program's main menu, but only include the choices relevant to the location you clicked. Therefore, contextual menus can be a quick and efficient way of selecting the option you need. So next time you use your favorite program, try right-clicking in different areas of the screen. You might find some pretty useful options you didn't even know existed!

A text file sent by a Web server that is stored on the hard drive of a computer and relays back to the Web server things about the user, his or her computer, and/or his or her computer activities.

It seems like everyone who tries to explain what a cookie is just has to make a joke out of it (because of the name), so I'm not even going to bother. In computer terminology, a cookie is data sent to your computer by a Web server that records your actions on a certain Web site. It's a lot like a preference file for a typical computer program. When you visit the site after being sent the cookie, the site will load certain pages according to the information stored in the cookie.

For example, some sites can remember information like your user name and password, so you don't have to re-enter it each time you visit the site. Cookies are what allow you to have personalized web sites like "My Excite" or "My Yahoo," where you can customize what is displayed on the page. While cookies have many benefits, some people don't like to have their information recorded by Web sites that they visit. For this reason, most Web browsers have an option to accept or deny cookies. Personally, I like cookies -- I think they taste great too.

Many software programs allow you to copy data, such as text in Microsoft Word or an image in Adobe Photoshop. To copy a piece of data, you need to first select it (or highlight it) and choose "Copy" from the Edit menu within the program. Most programs allow you to use the keyboard shortcut "Control-C" for Windows or "Command-C" for the Mac OS.

When you copy a piece of data, it is moved to a buffer in the system's memory called the "Clipboard." This is a temporary storage area in your computer's RAM that holds the most recent item that has been copied. Of course, copying isn't very helpful if you can't use the data somewhere else. To insert the copied data into a document, choose "Paste" from the Edit menu and the data will be pasted into the document.

Central Processing Unit. The brain of the computer.

Movable indicator on computer screen

The Cut command removes a selected object and copies it to the clipboard. It performs both a Delete and Copy operation at the same time. After data has been cut from a document, it can be pasted into another similar document. Objects like text, images, audio, and video selections can be cut. However, only editable items can be cut since the command removes the selection from the document.

Computer data is information processed or stored by a computer. This information may be in the form of text documents, images, audio clips, software programs, or other types of data. Computer data may be processed by the computer's CPU and is stored in files and folders on the computer's hard disk.

At its most rudimentary level, computer data is a bunch of ones and zeros, known as binary data. Because all computer data is in binary format, it can be created, processed, saved, and stored digitally. This allows data to be transferred from one computer to another using a network connection or various media devices. It also does not deteriorate over time or lose quality after being used multiple times.

A data type is a type of data. Of course, that is rather circular definition, and also not very helpful. Therefore, a better definition of a data type is a data storage format that can contain a specific type or range of values.

When computer programs store data in variables, each variable must be assigned a specific data type. Some common data types include integers, floating point numbers, characters, strings, and arrays. They may also be more specific types, such as dates, timestamps, boolean values, and varchar (variable character) formats.

Some programming languages require the programmer to define the data type of a variable before assigning it a value. Other languages can automatically assign a variable's data type when the initial data is entered into the variable. For example, if the variable "var1" is created with the value "1.25," the variable would be created as a floating point data type. If the variable is set to "Hello world!," the variable would be assigned a string data type. Most programming languages allow each variable to store a single data type. Therefore, if the variable's data type has already been set to an integer, assigning string data to the variable may cause the data to be converted to an integer format.

Data types are also used by database applications. The fields within a database often require a specific type of data to be input. For example, a company's record for an employee may use a string data type for the employee's first and last name. The employee's date of hire would be stored in a date format, while his or her salary may be stored as an integer. By keeping the data types uniform across multiple records, database applications can easily search, sort, and compare fields in different records.

Stands for "Double Data Rate." It is an advanced version of SDRAM, a type of computer memory. DDR-SDRAM, sometimes called "SDRAM II," can transfer data twice as fast as regular SDRAM chips. This is because DDR memory can send and receive signals twice per clock cycle. The efficient operation of DDR-SDRAM makes the memory great for notebook computers since it uses up less power.

Stands for "Double Data Rate 2." DDR2 RAM is an improved version of DDR memory that is faster and more efficient. Like standard DDR memory, DDR2 memory can send data on both the rising and falling edges of the processor's clock cycles. This nearly doubles the amount of work the RAM can do in a given amount of time. DDR and DDR2 are also both types of SDRAM, which allows them to run faster than conventional memory.

While DDR and DDR2 have many similarities, DDR2 RAM uses a different design than DDR memory. The improved design allows DDR2 RAM to run faster than standard DDR memory. The modified design also gives the RAM more bandwidth, which means more data can be passed through the RAM chip at one time. This increases the efficiency of the memory. Since DDR2 runs more efficiently than standard DDR memory, it actually uses less power than DDR memory, even though it runs faster. The only downside of DDR2 memory is that it is not compatible with standard DDR slots. So make sure your computer supports DDR2 RAM before upgrading your memory.

Stands for "Double Data Rate Type 3." DDR3 is an SDRAM specification introduced in 2007. Compared to previous DDR2 standard, DDR3 uses 30% less power and provides significantly faster data transfer speeds.

DDR3 memory modules are available in both DIMM and SO-DIMM form factors. DIMMs are commonly used for desktop PCs, while SO-DIMMs are typically used for laptops and all-in-one computers. While DDR3 DIMMs and SO-DIMM are the same size as their DDR2 counterparts, they are not compatible with DDR2 RAM slots. Fortunately, the connecting pins are arranged differently, so it is physical impossible to insert a DDR3 memory module into a a DDR2 RAM slot, and vice versa.

Several types of DDR3 memory exist, providing a range of maximum data transfer rates. The first version of DDR3 memory, called DDR3-800 (also "PC3-6400") provides peak transfer rates of of 6,400 MB/s. Other specifications include DDR3-1066, DDR3-1333, DDR3-1600, DDR3-1866, and DDR3-2133. DDR3-2133 (also called PC3-17000) supports peak transfer rates of 17,067 MB/s.

Computer programmers, like everybody else, are not perfect. This means the programs they write sometimes have small errors, called "bugs," in them. These bugs can be minor, such as not recognizing user input, or more serious, such as a memory leak that crashes the program. Before releasing their software to the public, programmers "debug" their programs, eliminating as many errors as possible. This debugging process often takes a long time, as fixing some errors may introduce others. Debugging your windshield at a gas station is much easier than debugging a computer program.

This term is used to describe a preset value for some option in a computer program. It is the value used when a setting has not been specified by the user. For example, the default font setting in Netscape Communicator is "Times." If you don't go to the Netscape preferences and change it to something else, the "Times" font will be used -- by default. Typically, default settings are set to what most people would choose anyway, so there's often no reason to change them. However, if you're one of those people who has to customize everything that you possibly can, then you can go ahead and change all the default settings you want.

"Default" can also be used as a verb. If a custom setting won't work for some reason, the program will "default" to the default setting. For example, say you're working on computer that is on a network and you print something when there is no printer specified. If you're lucky and don't get some nasty error message, the print job will default to the default printer and your work will be printed.

Your computer's desktop is much like a physical desktop. You probably keep a number of commonly used items on your desk such as pens, papers, folders, and other items. Your computer's desktop serves the same purpose -- to give you easy access to items on your hard drive. It is common to store frequently used files, folders, and programs on your desktop. This allows you to access the items quickly instead of digging through the directories on your hard drive each time you want to open them.

Both the Macintosh and Windows interfaces use the desktop as a central part of the interface. Both operating systems allow you to move items on and off the desktop as you wish and offer organization tools to arrange and clean up the items on the desktop. Yes, it would be nice if there was an option like that for a real-life desktop. You can also customize your computer's desktop with the pattern or background image of your choice. For more information on customizing your desktop, view this Help Center article.

As the name implies, a dialog box serves to initiate a dialog with the user. It is a window that pops up on the screen with options that the user can select. After the selections have been made, the user can typically click "OK" to enter the changes or "Cancel" to discard the selections. It is customary for menu options that include an ellipsis at the end, such as "Preferences..." or "Save As...", to open a dialog box when selected.

For example, if a user selects "Internet Options..." from the Options menu in Internet Explorer, a dialog box will pop up allowing the user to choose the default home page, change the security settings, empty the browser cache, and modify several other settings. Once the selections have been made, the user can click "OK" to use the new settings, or "Cancel" to discard the changes. Some Windows programs also have an "Apply" option that activates the selections without closing the dialog box.

When a user selects "Open..." from the File menu, an "Open dialog box" appears, allowing the user to browse the hard drive and other disks for files to open. When "Save As..." is chosen from the File menu, a "Close dialog box" pops up, allowing the user to type the name of the file and choose where to save it. While dialog boxes may not seem too exciting, they provide an intuitive way to communicate with the computer and are an essential part of today's computer interfaces.

Digital information is stored using a series of ones and zeros. Computers are digital machines because they can only read information as on or off -- 1 or 0. This method of computation, also known as the binary system, may seem rather simplistic, but can be used to represent incredible amounts of data. CDs and DVDs can be used to store and play back high-quality sound and video even though they consist entirely of ones and zeros.

Unlike computers, humans perceive information in analog. We capture auditory and visual signals as a continuous stream. Digital devices, on the other hand, estimate this information using ones and zeros. The rate of this estimation, called the "sampling rate," combined with how much information is included in each sample (the bit depth), determines how accurate the digital estimation is.

For example, a typical CD audio track is sampled at 44.1 KHz (44,100 samples per second) with a bit depth of 16 bits. This provides a high-quality estimation of an analog audio signal that sounds realistic the human ear. However, a higher-quality audio format, such as a DVD-Audio disc, may be sampled at 96 KHz and have a bit depth of 24 bits. The same song played on both discs will sound more smooth and dynamic on the DVD-Audio disc.

A directory is another name for a folder. Files on your hard disk are organized into various folders, or directories, so that it is easier to keep track of them. For example, you may keep your pictures in one folder and your music files in another folder. Folders can also contain other folders, allowing for more specific organization.

Since you can have folders within a folder, files on your hard drive are organized much like branches on a tree. The main directory on your hard drive is appropriately called the "root directory." Folders that exist within the root directory most likely contain other folders, which may branch out to even more folders.

DirectX is a set of standard commands and functions that software developers can use when creating their programs. While any Windows-based software program can include DirectX commands, they are usually used in video games. For example, developers may use DirectX for controlling video playback, sound effects, and peripheral input (such as a keyboard, mouse, or joystick). By incorporating DirectX functions into a computer game, programmers can use predefined commands to manage the video and sound of their game, as well as user input. This makes it easier for programmers to develop video games and also helps the games look more uniform, since DirectX games use many of the same commands.

Technically, DirectX is known as an application programming interface (API), which consists of predefined functions and commands. In order to create programs that use DirectX, software developers must use the DirectX software development kit, available from Microsoft. However, most users need only the DirectX "End-User Runtime" installed on their computer in order to run DirectX-enabled software. The DirectX API is available for Windows software and Xbox video games

Stands for "Dynamic Link Library." A DLL (.dll) file contains a library of functions and other information that can be accessed by a Windows program. When a program is launched, links to the necessary .dll files are created. If a static link is created, the .dll files will be in use as long as the program is active. If a dynamic link is created, the .dll files will only be used when needed. Dynamic links help programs use resources, such as memory and hard drive space, more efficiently.

DLL files can also be used by more than one program. In fact, they can even be used by multiple programs at the same time. Some DLLs come with the Windows operating system while others are added when new programs are installed. You typically don't want to open a .dll file directly, since the program that uses it will automatically load it if needed. Though DLL filenames usally end in ".dll," they can also end in .exe, .drv, and .fon, just to make things more confusing.

A document is a type of file that has been created or saved by an application. For example, a text file saved with Microsoft Word is considered a document, while a system library, such as a .DLL file, is not. Examples of documents include word processing files, spreadsheets, presentations, audio files, video files, and saved media projects.

Each document has filename, which identifies the file. It also includes an icon, which visually identifies the program associated with the file. In most cases, the document icon is generated by the program that created the document. When you double-click a document icon, it will open in the corresponding application.

Disk Operating System. An operating system designed for early IBM-compatible PCs.

Double clicking involves clicking your mouse button quickly two times. To perform a double click, and not just two clicks, the mouse button must be pressed twice within a very short time, typically about half a second. Most operating systems allow you to lengthen or shorten the maximum time allowed for a double click, using the Mouse Control Panel or System Preference.

A double click is recognized by your computer as a specific command, just like pressing a key on your keyboard. Double clicking is used to to perform a variety of actions, such as opening a program, opening a folder, or selecting a word of text. In order to double click an object, just move the cursor over the item and press the left mouse button quickly two times.

This is the process in which data is sent to your computer. Whenever you receive information from the Internet, you are downloading it to your computer. For example, you might have to download an upgrade for your computer's operating system in order to play a new game (especially if you're using Windows). Or you might download a demo version of a program you are thinking about buying from the software company's Web site. The opposite of this process, sending information to another computer, is called uploading.

Stands for "Dots Per Inch." DPI is used to measure the resolution of an image both on screen and in print. As the name suggests, the DPI measures how many dots fit into a linear inch. Therefore, the higher the DPI, the more detail can be shown in an image.

It should be noted that DPI is not dots per square inch. Since a 600 dpi printer can print 600 dots both horizontally and vertically per inch, it actually prints 360,000 (600 x 600) dots per square inch.

Also, since most monitors have a native resolution of 72 or 96 pixels per inch, they cannot display a 300 dpi image in actual size. Instead, when viewed at 100%, the image will look much larger than the print version because the pixels on the screen take up more space than the dots on the paper.

You can use your mouse to drag icons and other objects on your computer screen. Dragging icons from your desktop or an open window to another folder will move the objects to the new folder. You can also drag icons to the Trash (Mac) or the Recycle Bin (Windows) if you want to delete tehm. Some word processing programs allow you to select text and drag the selected text to another place in the document. To select the text, you may have to "drag" the mouse over the text you want to select.

This term usually refers to the person behind the wheel of a moving car. In the computer world, however, a driver is a small file that helps the computer communicate with a certain hardware device. It contains information the computer needs to recognize and control the device. In Windows-based PCs, a driver is often packaged as a dynamic link library, or .dll file. In Macs, most hardware devices don't need drivers, but the ones that do usually come with a software driver in the form of a system extension, or .kext file.

Stands for "Digital Video Interface." DVI is a video connection standard created by the Digital Display Working Group (DDWG). Most DVI ports support both analog and digital displays. If the display is analog, the DVI connection converts the digital signal to an analog signal. If the display is digital, no conversion is necessary.

There are three types of DVI connections: 1) DVI-A (for analog), 2) DVI-D (for digital), and 3) DVI-I (integrated, for both analog and digital). The digital video interface supports high bandwidth signals, over 160 MHz, which means it can be used for high resolution displays such as UXGA and HDTV. You may find DVI ports on video cards in computers as well as on high-end televisions.

It's hard to remember what our lives were like without e-mail. Ranking up there with the Web as one of the most useful features of the Internet, e-mail has become one of today's standard means of communication. Billions of messages are sent each year. If you're like most people these days, you probably have more than one e-mail address. After all, the more addresses you have, the more sophisticated you look...

E-mail is part of the standard TCP/IP set of protocols. Sending messages is typically done by SMTP (Simple Mail Transfer Protocol) and receiving messages is handled by POP3 (Post Office Protocol 3), or IMAP (Internet Message Access Protocol). IMAP is the newer protocol, allowing you to view and sort messages on the mail server, without downloading them to your hard drive.

Microsoft Excel is a spreadsheet program for Windows and Macintosh computers. It is part of the Microsoft Office suite, which includes other productivity programs, such as Word and PowerPoint.

Though Excel is developed by Microsoft, the first version of the program was released for the Macintosh in 1985. It wasn't until 1987, when Microsoft introduced Windows 3.0, that Excel was made available for Windows. Since then, Microsoft has supported the program on both platforms, releasing updates about every two years.

Facebook is a social networking website that was originally designed for college students, but is now open to anyone 13 years of age or older. Facebook users can create and customize their own profiles with photos, videos, and information about themselves. Friends can browse the profiles of other friends and write messages on their pages.

Each Facebook profile has a "wall," where friends can post comments. Since the wall is viewable by all the user's friends, wall postings are basically a public conversation. Therefore, it is usually best not to write personal messages on your friends' walls. Instead, you can send a person a private message, which will show up in his or her private Inbox, similar to an e-mail message.

Facebook allows each user to set privacy settings, which by default are pretty strict. For example, if you have not added a certain person as a friend, that person will not be able to view your profile. However, you can adjust the privacy settings to allow users within your network (such as your college or the area you live) to view part or all of your profile. You can also create a "limited profile," which allows you to hide certain parts of your profile from a list of users that you select. If you don't want certain friends to be able to view your full profile, you can add them to your "limited profile" list.

This strange term refers to the way Windows stores data on your hard drive. "FAT" stands for "File Allocation Table," which keeps track of all your files and helps the computer locate them on the disk. Even if a file gets fragmented (split up into various areas on the disk), the file allocation table still can keep track of it. FAT32 is an improvement to the original FAT system, since it uses more bits to identify each cluster on the disk. This helps the computer locate files easier and allows for smaller clusters, which improves the efficiency of your hard disk. FAT32 supports up to 2 terabytes of hard disk storage. Unless you are a serious power user, that should be more than enough space for you.

A file is a collection of data stored in one unit, identified by a filename. It can be a document, picture, audio or video stream, data library, application, or other collection of data. The following is a brief description of each file type.

Documents include text files, such as a Word documents, RTF (Rich Text Format) documents, PDFs, Web pages, and others. Pictures include JPEGs, GIFs, BMPs, and layered image files, such as Photoshop documents (PSDs). Audio files include MP3s, AACs, WAVs, AIFs, and several others. Video files can be encoded in MPEG, MOV, WMV, or DV formats, just to name a few.

A library file is a unit of data that is referenced by a specific program or the operating system itself. These include plug-ins, components, scripts, and many others. An application is a program, or executable file. Programs such as Microsoft Internet Explorer and Apple iTunes are both applications, but are also files.

Files can be opened, saved, deleted, and moved to different folders. They can also be transferred across network connections or downloaded from the Internet. A file's type can be determined by viewing the file's icon or by reading the file extension. If the file type is associated with a specific application, double-clicking the file will typically open the file within the program.

A file extension is the last part of a filename, after the dot (e.g. ".pdf"). Most file extensions are three characters long, but they can be shorter or longer as well. File extensions are used to define the file type of each file. The operating system uses this information to select which application will open the file and choose the appropriate icon for the file.

Visit the Sharpened File Extensions Reference to view an extensive list of file extensions and their associated file types.

A file format describes the way data is stored in a file. It defines the data structure (how the data is organized in the file) as well the type of data that the file contains. Some file formats are "open formats," meaning they are publicly available and can be used by all software developers. Other file formats are proprietary or "closed formats," meaning they can only be opened by specific applications.

There are two different ways of storing data in a file – as text or binary data. Text-based file formats, such as XML and HTML, store data as plain text, which means the file content can be viewed in a text editor. Binary files, on the other hand, can only be opened with a program that recognizes the specific file format. While some binary files can be opened in a text editor, most of the data will appear garbled and unintelligible.

Most people have several thousand files on their computer's hard disk, so imagine how hard it would be to find anything if the files were not organized. Fortunately, all hard disks use a file system, which organizes all the files on the disk. The file system is created when you initialize or format your hard disk. It sets up the root directory and subsequent directories beneath it. The file system allows you to create new files and folders, which are added to different parts of the "file tree" on your hard disk.

For example, your hard disk probably has separate folders for programs, documents, pictures, music, and movie files. Within these folders, there are likely other folders that futher organize your files. All these folders (or directories) are organized by your computer's file system. There are also several folders your computer's operating system uses to store system files, such as startup data and system preferences. Some of these folders are invisible to the user, but are recognized by the computer's file system.

Older Windows machines used a file system called FAT32, while newer Windows computers use NTFS. Macintosh computers used the HFS file system for a long time, but now use an updated version of HFS, called HFS+. Though you typically don't need to know all the details of your computer's file system, it is nice to know that it is always working to keep your files organized.

A file type, as the name implies, is a specific type of file. Some file types are associated with a single application, while others file types are universal and can be opened by several different programs. For example, a Microsoft PowerPoint presentation (saved with a .PPTX extension) is a proprietary file type that can only be opened by Microsoft PowerPoint. A rich text document (saved with an .RTF extension) is a universal file type that can be opened by most text editors.

You can often identify a file type by a file's extension. For example, a .DOCX file is a Microsoft Word document. ".DOCX" is the file extension, while "Microsoft Word document" is the file type. Proprietary file types typically include the program name in the file type, while universal file types do not. For example, a .JPG file is simply called a "JPEG image" since it is not associated with a specific application.

Important: While the terms "file type" and "file format" are often used interchangeably, a file format technically refers to the way data is stored within a file.

A filename is a text string that identifies a file. Every file stored on a computer's hard disk has a filename that helps identify the file within a given folder. Therefore, each file within a specific folder must have a different filename, while files in different folders can have the same name.

Filenames may contain letters, numbers, and other characters. Depending on the operating system, certain characters cannot be used since they conflict with operators or other syntax used by the operating system. Different operating systems also have different limits for the number of characters a filename can have. While older operating systems limited filenames to only 8 or 16 characters, newer OS's allow filenames to be as long as 256 characters. Of course, for most practical purposes, 16 characters is usually enough.

Filenames also usually include a file extension, which identifies the type of file. The file extension is also called the "filename suffix" since it is appended to the filename, following a dot or period. For example, a Microsoft Word document may be named "document1.doc." While technically the filename in the preceding example is "document1" and "doc" is the extension, it is also acceptable to refer to "document1.doc" as the filename. In some cases, the filename may even refer to the file's directory location, i.e. ("\My Documents\School Papers\document1.doc").

A structure for containing electronic files. In some operating systems, it is called a directory.

Just like real world folders, folders on your hard drive store files. These files can be documents, programs, scripts, libraries, and any other kind of computer file you can think of. Folders can also store other folders, which may store more files or other folders, and so on.

Folders allow people to organize their files in a way that makes sense to them. For example, a college student might store all her photos in a folder named "Pictures," all her papers in a folder named "School Work," and all her financial information (including the tens of thousands of dollars in student loans) in a folder named "Finances." All these folders might reside within a folder called "My Documents."

The computer's operating system also uses folders to store data such as system files, library files, and user preferences. Often, the folders that the system uses are locked, meaning users cannot alter their contents.

A font is a specific typeface of a certain size and style. For example, one font may be Arial 12 pt bold, while another font may be Times New Roman 14 pt italic.

Most word processing programs have a Font menu that allows you to choose the typeface, size, and style of the text. In order to use a font, you must have it installed on your computer. Windows provides access to fonts using the Fonts control panel. The Mac OS stores fonts in a Fonts folder and includes a separate "Font Book" application for managing fonts.

Sets of typefaces (or characters) that come in different styles and sizes.

A formula is a calculation performed on one or more variables. It may be a simple operation, such as the addition of two numbers, or a complex calculation involving several operations. Formulas are often used within functions to process data within the function. They receive input from the function and return the resulting output. Formulas may also be placed in cells within a spreadsheet to calculate values based on the data stored in other cells.

Software created by people who are willing to give it away for the satisfaction of sharing or knowing they helped to simplify other people's lives. It may be free-standing software, or it may add functionality to existing software.

Like shareware, freeware is software you can download, pass around, and distribute without any initial payment. However, the great part about freeware is that you never have to pay for it. No 30 day limit, no demo versions, no disabled features -- it's totally free. Things like minor program updates and small games are commonly distributed as freeware. Though freeware does not cost anything, it is still copyrighted, so other people can't market the software as their own.

Frequency is the number times something occurs in a specific amount of time. In computing, frequency is used to measure processing speed, such as the clock speed of a CPU. For example, a 3.2 GHz processor has a frequency of 3.2 gigahertz, or 3,200,000,000 hertz. This means the processor performs 3,200,000,000 cycles each second. Since most instructions require multiple cycles, the number of instructions per second is typically less than the number of clock cycles. Therefore, MIPS, which measures instructions per second, is sometimes used to measure raw computing performance.

Frequency is also used to measure oscillation rates of waves within the electromagnetic spectrum. Some examples include radio waves, microwaves, visible light, and ultraviolet rays. FM radio broadcasts in the range of 87.5 to 108 megahertz. When you tune to 93.7, for example, you are instructing your radio to only receive signals that have an oscillation frequency of 93,700,000 hertz. Wi-Fi signals are broadcast at either 2.4 GHz or 5 GHz, both of which are much higher than the FM radio frequency band. The higher frequency prevents wireless interference and provides a stronger, more reliable signal over shorter distances.

File Transfer Protocol, a format and set of rules for transferring files from a host to a remote computer.

A gibibyte is a unit of data storage that equals 2 to the 30th power, or 1,073,741,824 bytes.

While a gigabyte can be estimated as 10^9 or 1,000,000,000 bytes, a gibibyte is defined as exactly 1,073,741,824 bytes. This helps avoid the ambiguity associated with the size of gigabytes. A gibibyte is 1,024 mebibytes and precedes the tebibyte unit of measurement.

The letters "GIF" actually stand for "Graphics Interchange Format," but you don't need to remember that. What you should know is that a GIF is a compressed image file format. GIF images use a compression formula originally developed by CompuServe (which is why you see the term "CompuServe GIF" in Photoshop, for those of you that care). GIFs are based on indexed colors, which is a palette of at most 256 colors. This helps greatly reduce their file size. These compressed image files can be quickly transmitted over a network or the Internet, which is why you often see them on Web pages. GIF files are great for small icons and animated images, but they lack the color range to be used for high-quality photos.

A gigabyte is 2 to the 30th power, or 1,073,741,824 bytes.

It can be estimated as 10 to the 9th power, or one billion (1,000,000,000) bytes. A gigabyte is 1,024 megabytes and precedes the terabyte unit of measurement. Hard drive sizes are typically measured in gigabytes, such as a 160GB or 250GB drive. The term gigabyte is often often abbreviated as simply a "gig" in speech. For example, if you have a 250GB hard drive, you could say, "I have 250 gigs of disk space." The prefix "giga" comes from the Greek word "gigas," meaning giant.

1024 megabytes.

One gigahertz is equal to 1,000 megahertz (MHz) or 1,000,000,000 Hz. It is commonly used to measure computer processing speeds. For many years, computer CPU speeds were measured in megahertz, but after personal computers eclipsed the 1,000 Mhz mark around the year 2000, gigahertz became the standard measurement unit. After all, it is easier to say "2.4 Gigahertz" than "2,400 Megahertz."

While gigahertz is most commonly used to measure processor speed, it can also measure the speed of other parts of the computer, such as the RAM and backside cache. The speed of these components, along with other parts of the computer, also impact the computer's overall performance. Therefore, when comparing computers, remember the number of gigahertz is not the only thing that matters.

Google is the world's most popular search engine. It began as a search project in 1996 by Larry Page and Sergey Brin, who were two Ph.D. students at Stanford University. They developed a search engine algorithm that ranked Web pages not just by content and keywords, but by how many other Web pages linked to each page. This strategy produced more useful results than other search engines, and led to a rapid increase in Google's Web search marketshare. The Google ranking algorithm was later named "PageRank" and was patented in September of 2001. In only a short time, Google became the number one search engine in the world.

According to Google's website, the company's mission is to "organize the world's information and make it universally accessible and useful." While the Web search remains Google's primary tool for helping users access information, the company offers several other services as well. Some of these include:

• Froogle - price comparison shopping
• Image Search - search for images on the Web
• Google Groups - online discussion forums
• Google Answers - answers to questions based on a bidding system
• Google Maps - maps and directions
• Google Toolbar - a downloadable search tool
• Blogger - a free blogging service
• Gmail - Web-based e-mail with several gigabytes of storage
• AdWords - Advertising services for advertisers
• AdSense - Advertising services for Web publishers

Google has become such a popular search engine that the term "Google" is now often used as a verb, synonymous with "search." For example, if you are looking for information about someone, you can Google that person using Google's search engine.

Computer graphics are images displayed on a computer screen. They can be either two or three-dimensional. Two-dimensional graphics come in raster or vector formats.

Raster graphics are the most common type of computer graphic and are used for icons, photos, and other basic images. Vector graphics are used for drawings, logos, and other scalable objects. 3D graphics are made up of polygons and can be created with CAD and 3D modeling programs. They are most commonly seen in video games and 3D animations.

Graphical User Interface, a system that simplifies selecting computer commands by enabling the user to point to symbols or illustrations (called icons) on the computer screen with a mouse.

While this term originally referred to a clever or expert programmer, it is now more commonly used to refer to someone who can gain unauthorized access to other computers. A hacker can "hack" his or her way through the security levels of a computer system or network. This can be as simple as figuring out somebody else's password or as complex as writing a custom program to break another computer's security software. Hackers are the reason software manufacturers release periodic "security updates" to their programs. While it is unlikely that the average person will get "hacked," some large businesses and organizations receive multiple hacking attempts a day.

The hard drive is what stores all your data. It houses the hard disk, where all your files and folders are physically located. A typical hard drive is only slightly larger than your hand, yet can hold over 100 GB of data. The data is stored on a stack of disks that are mounted inside a solid encasement. These disks spin extremely fast (typically at either 5400 or 7200 RPM) so that data can be accessed immediately from anywhere on the drive. The data is stored on the hard drive magnetically, so it stays on the drive even after the power supply is turned off.

The term "hard drive" is actually short for "hard disk drive." The term "hard disk" refers to the actual disks inside the drive. However, all three of these terms are usually seen as referring to the same thing -- the place where your data is stored. Since I use the term "hard drive" most often, that is the correct one to use.

The physical and mechanical components of a computer system, such as the electronic circuitry, chips, monitor, disks, disk drives, keyboard, modem, and printer.

HDD is short for "hard disk drive." An HDD is a storage device used to store data. Unlike RAM, which requires electrical power to maintain its state, a hard disk drive stores data magnetically. Therefore, it retains its data when the power source is turned off or disconnected.

Most computers include either an HDD or an SSD that stores your files. For example, if your computer has an internal HDD, when you save a file, it is written to the hard disk drive. Additionally, the HDD stores pre-installed applications and other programs you add to your computer. Since modern HDDs have storage capacities of more than one terabyte, most users do not even come close to running out of disk space. However, if necessary, you can connect an external HDD (often called and external hard drive for additional storage or for backup purposes.

Important: The term "hard disk drive" may be used synonymously with the terms "hard drive" and "hard disk." Technically, an HDD and a hard drive refer to the same thing, while a hard disk refers to the actual magnetic platter inside the drive case.

Stands for "High-Definition Multimedia Interface." HDMI is a digital interface for transmitting audio and video data in a single cable. It is supported by most HDTVs and related components, such as DVD and Blu-ray players, cable boxes, and video game systems.

While other types of A/V connections require separate cables for audio and video data, HDMI carries the audio and video streams together, greatly eliminating cable clutter. For example, a component cable connection requires three cables for video and two for audio, totaling five cables in all. The same information can be transmitted using one HDMI cable.

Because HDMI is a digital connection, HDMI cables are less prone to interference and signal noise than analog cables. Also, since most components, such as DVD players and digital cable boxes process information digitally, using HDMI eliminates the analog to digital conversion other interfaces require. Therefore, HDMI often produces the best quality picture and sound compared to other types of connections.

HDMI cables are typically more expensive than analog cables, largely because they cost more to manufacture. But it is important to remember that with HDMI, you don't need to buy separate audio and video cables. Besides, the single all-purpose connection may alone be worth the difference to those who don't like dealing with confusing cables and connections. Just remember that before you buy an HDMI cable, make sure the devices you are connecting have HDMI connections available.

Hexadecimal is a base-16 number system. It is a different method of representing numbers than the base-10 system we use in every day practice. In base-10, we count in multiples of 10 before adding another digit. For example, "8 - 9 - 10 - 11 - 12..." and "98 - 99 - 100 - 101 - 102..." Notice how a new digit is added when the number 10 is reached, and another digit is added to represent 100 (10x10). In base-16, or the hexadecimal number system, each digit can have sixteen values instead of ten. The values of a hexadecimal digit can be:

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F

Therefore, the number 12 (in the common base-10 format) would be represented as "C" in hexadecimal notation. The number 24 would be 18 (16+8). 100 is 64 in hexadecimal (16x6 + 4) and 1000 is 3E8 (256x3 + 16x14 + 8).

While computers process numbers using the base-2, or binary system, it is often more efficient to visually represent the numbers in hexadecimal format. This is because it only takes one hexadecimal digit to represent four binary digits. Since there are eight binary digits in a byte, only two hexadecimal digits are needed to represent one byte.

The main page of a Web site used to greet visitors, provide information about the site, or to direct the viewer to other pages on the site.

Hypertext Markup Language, a standard of text markup conventions used for documents on the World Wide Web.

Browsers interpret the codes to give the text structure and formatting (such as bold, blue, or italic).

Hypertext Transfer Protocol, a common system used to request and send HTML documents on the World Wide Web.

It is the first portion of all URL addresses on the World Wide Web.

Text or an image that is connected by hypertext coding to a different location. By selecting the text or image with a mouse, the computer jumps to (or displays) the linked text.

A system for organizing text through links, as opposed to a menu-driven hierarchy such as Gopher.

Most Web pages include hypertext links to other pages at that site, or to other sites on the World Wide Web.

Stands for "Input/Output" and is pronounced simply "eye-oh." Computers are based on the fundamental idea that every input results in an output. For example, if you are running a word processor program and type a sentence on your keyboard, the text will appear on the screen. The keyboard is an input device and the screen is an output device. You might also print the text using a printer, which is another output device. The computer's CPU handles all the I/O operations, sending the data it receives to the correct path. The path may be to the video card, to the hard drive, or to the RAM, just to name a few.

The ports on the outside of a computer are commonly referred to as "I/O ports" because they are what connect input and output devices to the computer. Software developers use I/O to describe how a program will function, depending on what a user enters. For example, if the user presses the space bar key in a game, say "Super Jumper Man," the character on the screen will jump. Multiply that by several thousand other scenarios of user input and you have yourself a computer game.

Symbols or illustrations appearing on the computer screen that indicate program files or other computer functions.

Whenever you enter data into your computer, it is referred to as input. This can be text typed in a word processing document, keywords entered in a search engine's search box, or data entered into a spreadsheet. Input can be something as simple as moving the mouse or clicking the mouse button or it can be as complex as scanning a document or downloading photos from a digital camera.

Devices such as the keyboard, mouse, scanner, and even a digital camera are considered input devices. This is because they allow the user to input data into the computer (yes, the word "input" can also be used as a verb). While input generally comes from humans, computers can also receive input from other sources. These include audio and video devices that record movies and sound, media discs that install software, and even the Internet, which is used to download files and receive data such as e-mail or instant messages.

The opposite of input is output, which is what the computer produces based on user input. Input and output devices are collectively referred to as I/O devices.

Most software programs require that you first install them on your computer before using them. For example, if you buy Microsoft Office, you need to install it on your computer before you can run any of the included programs such as Word or Excel. You can install software from a CD or DVD, an external hard drive, or from a networked computer. You can also install a program or software update from a file downloaded from the Internet.

Installing a software program writes the necessary data for running the program on your hard drive. Often the installer program will decompress the data included with the installer immediately before writing the information to your hard drive. Software updates, which are typically downloaded from the Internet, work the same way. When you run the update, the installer file decompresses the data and then updates the correct program or operating system.

An integer is a whole number (not a fraction) that can be positive, negative, or zero. Therefore, the numbers 10, 0, -25, and 5,148 are all integers. Unlike floating point numbers, integers cannot have decimal places.

Integers are a commonly used data type in computer programming. For example, whenever a number is being incremented, such as within a "for loop" or "while loop," an integer is used. Integers are also used to determine an item's location within an array.

When two integers are added, subtracted, or multiplied, the result is also an integer. However, when one integer is divided into another, the result may be an integer or a fraction. For example, 6 divided by 3 equals 2, which is an integer, but 6 divided by 4 equals 1.5, which contains a fraction. Decimal numbers may either be rounded or truncated to produce an integer result.

The interconnections that allow a device, a program, or a person to interact. Hardware interfaces are the cables that connect the device to its power source and to other devices.

Software interfaces allow the program to communicate with other programs (such as the operating system), and user interfaces allow the user to communicate with the program (e.g., via mouse, menu commands, icons, voice commands, etc.).

An international conglomeration of interconnected computer networks. Begun in the late 1960s, it was developed in the 1970s to allow government and university researchers to share information.

The Internet is not controlled by any single group or organization. Its original focus was research and communications, but it continues to expand, offering a wide array of resources for business and home users.

An Internet Protocol address is a unique set of numbers used to locate another computer on a network. The format of an IP address is a 32-bit string of four numbers separated by periods. Each number can be from 0 to 255 (i.e., 1.154.10.255). Within a closed network IP addresses may be assigned at random, however, IP addresses of web servers must be registered to avoid duplicates.

Stands for "International Organization for Standardization." Yes, technically the acronym should be "IOFS," but I guess ISO sounds better. The ISO works with standards institutes from over 150 countries to develop technology and product standards. These standards lead to a more efficient, safer, and cleaner development of products. It also leads to more standardized products for consumers.

The ISO is important to the computer industry, since the organization standardizes many of the technologies used by your computer hardware and software. For example, the ISO 9660 standard defines a file system used by CD-ROM media. CDs formatted using this standard can be used on any operating system that supports the ISO 9660 standard, including Windows, Mac, and Unix systems.

The ISO is similar to the IEEE, but performs a much broader range of standardizations. To find out more about the International Organization for Standardization, visit the ISO home page.

Stands for "Information Technology," and is pronounced "I.T." It refers to anything related to computing technology, such as networking, hardware, software, the Internet, or the people that work with these technologies. Many companies now have IT departments for managing the computers, networks, and other technical areas of their businesses. IT jobs include computer programming, network administration, computer engineering, Web development, technical support, and many other related occupations. Since we live in the "information age," information technology has become a part of our everyday lives. That means the term "IT," already highly overused, is here to stay.

Iteration is the repetition of a function or process in a computer program. Iterations of functions are common in computer programming, since they allow multiple blocks of data to be processed in sequence. This is typically done using a "while loop" or "for loop" (see the examples below). These loops will repeat a process until a certain number or case is reached. Recursive functions also use iteration, though instead of repeating a process, the entire function repeats itself.

While loop:   while (x < 30) { ... x++; }
For loop:   for (x=0; x<30; x++) { ... }

A practical example of how iterations are used is a PHP Web page that lists data from a table in a database. In order to display the table on the Web, the function might write each row in HTML using data from the database until the last row of data is reached. In this case, each row of the table would be created by an iteration of the PHP function.

Iterated functions are frequently used in both Web scripts and software programs. They can be simple functions like the one in the example above or complex loops that contain nested loops, which may call additional functions. The amazing thing is that even these complex loops typically only take a fraction of a second to complete.

An object-oriented programming language designed specifically for programs (particularly multimedia) to be used over the Internet. Java allows programmers to create small programs or applications (applets) to enhance Web sites.

While most of the world uses "Java" as another term for coffee, the computer science world uses it to refer to a programming language developed by Sun Microsystems. The syntax of Java is much like that of C/C++, but it is object-oriented and structured around "classes" instead of functions. Java can also be used for programming applets -- small programs that can be embedded in Web sites. The language is becoming increasingly popular among both Web and software developers since it is efficient and easy-to-use.

Java is a great programming language, but like Reading Rainbow says, you don't have to take my word for it. Sun Micorsystems describes Java as a "simple, object-oriented, distributed, interpreted, robust, secure, architecture-neutral, portable, high-performance, multithreaded, dynamic, buzzword-compliant, general-purpose programming language." And it removes stains like magic.

Like Java, this is a programming language designed by Sun Microsystems, in conjunction with Netscape, that can be integrated into standard HTML pages. While JavaScript is based on the Java syntax, it is a scripting language, and therefore cannot be used to create stand-alone programs. Instead, it is used mainly to create dynamic, interactive Web pages. For example, Web developers can use JavaScript to validate form input, create image rollovers, and to open those annoying pop-up windows. Like so many other things, we have to take the good with the bad.

Stands for "Kilobits Per Second." Don't confuse this with Kilobytes per second (which is 8 times more data per second). This term is commonly used in describing data transfer rates. For example, two common modem speeds are 33.6 Kbps and 56 Kbps.

As the name implies, a keyboard is basically a board of keys. Along with the mouse, the keyboard is one of the primary input devices used with a computer. The keyboard's design comes from the original typewriter keyboards, which arranged letters and numbers in a way that prevented the type-bars from getting jammed when typing quickly. This keyboard layout is known as the QWERTY design, which gets its name from the first six letters across in the upper-left-hand corner of the keyboard.

While the design of computer keyboards may have come from typewriters, today's keyboards have many other keys as well. Modifier keys, such as Control, Alt/Option, and Command (Mac) or the Windows key (Windows) can be used in conjunction with other keys as "shortcuts" to perform certain operations. For example, pressing Command-S (Mac), or Control-S (Windows) typically saves a document or project you are working on. Most of today's computer keyboards also have a row of function keys (F1 through F16) along the top of the keyboard, arrow keys arranged in an upside-down T, and a numeric keypad on the right-hand side. Some keyboards have even more buttons, allowing you to change the system volume, eject a CD, or open programs such as your e-mail or Web browser.

A keyboard shortcut is a key combination that performs a certain command, such as closing a window or saving a file. For example, pressing "Control-S" in a Windows program or "Command-S" on the Mac is the standard shortcut for saving an open document. You can also usually close a window on the Mac by pressing "Command-W" or by pressing "Alt-F4" in Windows. The shortcut for copying data is usually "Control-C" (Windows) or "Command-C" (Mac) and for pasting data, it is "Control-V" (Windows) or "Command-V" (Mac).

Most keyboard shortcuts are shortcuts for commands located in a program's menu bar. For example, most of the commands within the File and Edit menus have standard shortcuts. Each command that has a keyboard shortcut usually has the shortcut listed next to the command in the menu. For example, the Save option in a Windows program will usually have the text "Ctrl+S" next to it, indicating that pressing Control and S together will save the document.

While most keyboard shortcuts are located in a program's menu bar, there are many keyboard shortcuts that are sometimes not visible to the user. To view a list of keyboard shortcuts available for the Macintosh and Windows operating systems, view the pages below:

Mac OS X Keyboard Shortcuts | Windows XP Keyboard Shortcuts

A keystroke is typing one character on a keyboard (not stroking your keyboard like a cat). Every time you hit a key, you perform a keystroke. Therefore, 5400 keystrokes in one hour means hitting 5400 keys in one hour, or 90 keys a minute (5400 ÷ 60 minutes).

Sometimes keystrokes per hour (KSPH) or keystrokes per minute (KSPM) are used to measure typing speed instead of words per minute (WPM). After all, typing the word "hi" 50 times doesn't take quite as long as typing "Nebuchadnezzar" 50 times.

A kilobyte is 2 to the 10th power, or 1,024 bytes.

"But doesn't 'kilo' mean one thousand?" you ask. Well yes, but in the computer world, certain rules and guidelines don't have the same influence they do in other areas of life. Just ask any computer programmer. A kilobyte is technically 1,024 bytes because it is measured by 2^10, which equals 1,024. However, kilobytes are often estimated as 10 to the 3rd power, or 1,000 bytes. While this makes it easier to add kilobytes together, estimating can throw off larger measurements. This is because 1,024 kilobytes equal one megabyte, 1,024 megabytes equal one gigabyte, and so on.

Most small files on your computer are measured in kilobytes. For example, thumbnail images might use only 5 to 10KB of space. A larger 900x600 pixel JPEG image can take up 250KB of space. Text files are often less than 1KB. Most documents you save on your computer should be between 1 and 1,024KB. Anything larger than 1,024KB is measured in megabytes.

Equal to 1,024 bytes.

Stands for "Liquid Crystal Display." LCDs are super-thin displays that are used in laptop computer screens and flat panel monitors. Smaller LCDs are used in handheld TVs, PDAs, and portable video game devices. The image on an LCD screen is created by sandwiching an electrically reactive substance between two electrodes. This color of this substance can be changed by increasing or reducing the electrical current. Since LCD screens are based on the principle of blocking light (rather than emitting it), they use up much less power than standard CRT (Cathode-Ray Tube) monitors.

LinkedIn is a business-oriented social networking website. It allows you to create a custom profile and add other LinkedIn users to your list of connections. Unlike Facebook, LinkedIn profiles are designed to be professional, rather than personal. They appear like a resume, with education and work experience being the most prominent. By using LinkedIn, you can keep in touch with past colleagues and meet new potential business partners.

A UNIX - like, open-source operating system developed primarily by Linus Torvalds. Linux is free and runs on many platforms, including both PCs and Macintoshes. Linux is an open-source operating system, meaning that the source code of the operating system is freely available to the public. Programmers may redistribute and modify the code, as long as they don't collect royalties on their work or deny access to their code. Since development is not restricted to a single corporation more programmers can debug and improve the source code faster.

Logic gates perform basic logical functions and are the fundamental building blocks of digital integrated circuits. Most logic gates take an input of two binary values, and output a single value of a 1 or 0. Some circuits may have only a few logic gates, while others, such as microprocessors, may have millions of them. There are seven different types of logic gates, which are outlined below.

In the following examples, each logic gate except the NOT gate has two inputs, A and B, which can either be 1 (True) or 0 (False). The resulting output is a single value of 1 if the result is true, or 0 if the result is false.

1. AND - True if A and B are both True

    

    

2. OR - True if either A or B are True

    

    

3. NOT - Inverts value: True if input is False; False if input is True

    

    

4. XOR - True if either A or B are True, but False if both are True

    

    

5. NAND - AND followed by NOT: False only if A and B are both True

    

    

6. NOR - OR followed by NOT: True only if A and B are both False

    

    

7. XNOR - XOR followed by NOT: True if A and B are both True or both False

By combining thousands or millions of logic gates, it is possible to perform highly complex operations. The maximum number of logic gates on an integrated circuit is determined by the size of the chip divided by the size of the logic gates. Since transistors make up most of the logic gates in computer processors, smaller transistors mean more complex and faster processors.

A sequence of instructions that is repeated until a prescribed condition, such as agreement with a data element or completion of a count, is satisfied

An operating system with a graphical user interface, developed by Apple for Macintosh computers. Current System X.1.(10) combines the traditional Mac interface with a strong underlying UNIX. Operating system for increased performance and stability.

This is the name of the computers that are made by Apple Computer. The first Macintosh was introduced in 1984 and was seen as a major innovation in computing ease-of-use. The Macintosh was the first personal computer to use a graphical user interface (GUI), which allowed the user to interact with the operating system by using a mouse to click and drag objects. Since 1984, Apple has continually revised and upgraded the Macintosh product line and now makes both laptop and desktop versions of the Macintosh. The Macintosh product line includes the following models:

1. Power Mac - a high-performance desktop computer for professionals
2. PowerBook - a high-performance laptop computer for professionals.
3. iMac - a creatively designed consumer desktop computer
4. iBook - a laptop computer for students and home users
5. eMac - an all-in-one desktop computer for educators and entry-level consumers
6. Mac mini - a super-small, fully functional computer sold without a monitor, keyboard, or mouse

Apple also makes other equipment such as displays, MP3 players, and networking hardware, but the Macintosh is the heart and soul of the company. Macintosh computers run the Macintosh operating system, creatively named the "Mac OS."

Macro has two computer-related definitions, both of which involve making your computer experience more efficient.

1. A Keyboard Shortcut

The term "macro" is often used synonymously with "keyboard shortcut." Keyboard shortcuts are key combinations that perform commands, such as saving a file, closing a window, or copying and pasting data. For a list of keyboard shortcuts available for Mac and Windows, view the pages below:

- Mac OS X Keyboard Shortcuts
- Windows XP Keyboard Shortcuts

2. A Small Program

A macro can also be a small program, or script, that automates common tasks. These scripts are usually run within programs and can often be created by the user. For example, a user might record a macro for Microsoft Word that inserts his entire address when he presses a custom key combination. A Microsoft Excel user might record a macro to format the data in the selected column of a spreadsheet.

While Word and Excel both make it easy to create custom macros, many other programs allow users to create macros as well. However, not all programs refer to the automated commands as macros. For example, Photoshop allows users to record changes made to an image and saves the series of steps as an "action." These actions can then by applied to other images. Regardless of what they are called, macros can save you a lot of time by automating repetitive tasks. If you find yourself doing the same thing over and over again when using a certain program, you may want to simplify the process by recording a macro.

Short for "malicious software," malware refers to software programs designed to damage or do other unwanted actions on a computer system. In Spanish, "mal" is a prefix that means "bad," making the term "badware," which is a good way to remember it (even if you're not Spanish).

Common examples of malware include viruses, worms, trojan horses, and spyware. Viruses, for example, can cause havoc on a computer's hard drive by deleting files or directory information. Spyware can gather data from a user's system without the user knowing it. This can include anything from the Web pages a user visits to personal information, such as credit card numbers.

It is unfortunate that there are software programmers out there with malicious intent, but it is good to be aware of the fact. You can install anti-virus and anti-spyware utilities on your computer that will seek and destroy the malicious programs they find on your computer. So join the fight against badware and install some protective utilities on your hard drive!

Executable input, usually a mathematical expression, that Maple evaluates.

The result of an executed Maple input command. By default, Maple output is displayed in blue type in 2-D Math notation.

A collection of routines or commands that can be used in Maple. Most Maple packages provide a set of commands for a particular mathematical or scientific domain, or field of study.

Stands for "Megabits Per Second." One megabit is equal to one million bits or 1,000 kilobits. While "megabit" sounds similar to "megabyte," a megabit is roughly one eighth the size of a megabyte (since there are eight bits in a byte). Mbps is used to measure data transfer speeds of high bandwidth connections, such as Ethernet and cable modems.

A megabyte is 2 to the 20th power, or 1,048,576 bytes.

It can be estimated as 10 to the 6th power, or one million (1,000,000) bytes. A megabyte is 1,024 kilobytes and precedes the gigabyte unit of measurement. Large computer files are typically measured in megabytes. For example, a high-quality JPEG photo from a 6.3 megapixel digital camera takes up about 3MB of space. A four minute CD-quality audio clip takes up about 40MB of space and CDs can hold up to 700MB of space.

For a list of all the different units of measurements, view this Help Center article.

Abbreviation: MB

Equal to 1,048,576 bytes, usually rounded off to one million bytes (also called a meg).

Temporary storage for information, including applications and documents. The information must be stored to a permanent device, such as a hard disc or CD-ROM before the power is turned off, or the information will be lost. Computer memory is measured in terms of the amount of information it can store, commonly in megabytes or gigabytes.

A context-related list of options that users can choose from.

Metadata describes other data. It provides information about a certain item's content. For example, an image may include metadata that describes how large the picture is, the color depth, the image resolution, when the image was created, and other data. A text document's metadata may contain information about how long the document is, who the author is, when the document was written, and a short summary of the document.

Web pages often include metadata in the form of meta tags. Description and keywords meta tags are commonly used to describe the Web page's content. Most search engines use this data when adding pages to their search index.

A metafile can refer to two different types of computer files. The first is a file that describes the contents of other files. This type of metafile may contain metadata, which defines a group other files and gives a summary of what data they contain.

The second type of metafile is most often used in computer graphics. These files define objects and images using a list of coordinates. They are typically used for vector images, such as Adobe Illustrator, CorelDRAW, and EPS files, but can include raster images as well.

An abbreviation for Megahertz, or one million hertz. One MHz represents one million clock cycles per second and is the measure of a computer microprocessor's speed. For example, a microprocessor that runs at 300 MHz executes 300 million cycles per second. Each instruction a computer receives takes a fixed number of clock cycles to carry out, therefore the more cycles a computer can execute per second, the faster its programs run. Megahertz is also a unit of measure for bandwidth.

The largest independent software producer in the world, founded by Paul Allen and Bill Gates in 1975. Microsoft produces a very wide range of software products ultimately based on its Windows operating system.

A device that connects two computers together over a telephone or cable line by converting the computer's data into an audio signal. Modem is a contraction for the process it performs : modulate-demodulate.

A video display terminal.

Stands for "Modular Object-Oriented Dynamic Learning Environment." Moodle is an open source course management system, originally developed by Martin Dougiamas. It is used by thousands of educational institutions around the world to provide an organized interface for e-learning, or learning over the Internet.

Moodle allows educators to create online courses, which students can access as a virtual classroom. A typically Moodle home page will include a list of participants (including the teacher and students) and a calendar with a course schedule and list of assignments. Other Moodle features include online quizzes, forums, where students can post comments and ask questions, glossaries of terms, and links to other Web resources.

Because Moodle is open source, or freely distributed, it can be an attractive alternative to commercial e-learning options. To learn more about Moodle, visit Moodle.org.

The motherboard is the main circuit board of your computer and is also known as the mainboard or logic board. If you ever open your computer, the biggest piece of silicon you see is the motherboard. Attached to the motherboard, you'll find the CPU, ROM, memory RAM expansion slots, PCI slots, and USB ports. It also includes controllers for devices like the hard drive, DVD drive, keyboard, and mouse. Basically, the motherboard is what makes everything in your computer work together.

Each motherboard has a collection of chips and controllers known as the chipset. When new motherboards are developed, they often use new chipsets. The good news is that these boards are typically more efficient and faster than their predecessors. The bad news is that older components often do not work with new chipsets. Of course, if you are planning on upgrading multiple components, it may be more cost-effective to just buy a new computer.

A small hand-held device, similar to a trackball, used to control the position of the cursor on the video display; movements of the mouse on a desktop correspond to movements of the cursor on the screen.

Compact audio and video file format. The small size of the files makes them easy to download and e-mail. Format used in portable playback devices.

Stands for "Moving Picture Experts Group." The MPEG organization, which works with the International Organization for Standardization (ISO), develops standards for digital audio and video compression. The group constantly works to develop more efficient ways to digitally compress and store audio and video files.

The term MPEG also refers to a type of multimedia file, which is denoted by the file extension ".mpg" or ".mpeg." These files are compressed movies that can contain both audio and video. Though they are compressed, MPEG files maintain most of the original quality of the uncompressed movie. This is why many videos on the Web, such as movie trailers and music videos, are available in the MPEG format.

File extensions: .MPG, .MPE, .MPEG

An early operating system developed by Microsoft Corporation (Microsoft Disc Operating System).

Software programs that combine text and graphics with sound, video, and animation. A multimedia PC contains the hardware to support these capabilities.

A system of interconnected computers.

A network topology describes the arrangement of systems on a computer network. It defines how the computers, or nodes, within the network are arranged and connected to each other. Some common network topologies include star, ring, line, bus, and tree configurations. These topologies are defined below:

1. Star - One central note is connected to each of the other nodes on a network. Similar to a hub connected to the spokes in a wheel.
2. Ring - Each node is connected to exactly two other nodes, forming a ring. Can be visualized as a circular configuration. Requires at least three nodes.
3. Line - Nodes are arranged in a line, where most nodes are connected to two other nodes. However, the first and last node are not connected like they are in a ring.
4. Bus - Each node is connected to a central bus that runs along the entire network. All information transmitted across the bus can be received by any system in the network.
5. Tree - One "root" node connects to other nodes, which in turn connect to other nodes, forming a tree structure. Information from the root node may have to pass through other nodes to reach the end nodes.

It is helpful for a network administrator to know the pros and cons of different network topologies when putting together a network. By weighing the benefits of each type, the administrator can choose the configuration that is most efficient for the network's intended purpose.

Stands for "New Technology File System." NTFS is a file system introduced by Microsoft with Windows NT and is supported by subsequent versions of Windows, such as Windows 2000 and Windows XP. NTFS has a number of advantages over the previous file system, named FAT32 (File Allocation Table). One major advantage of NTFS is that it includes features to improve reliablity. For exmaple, the new technology file system includes fault tolerance, which automatically repairs hard drive errors without displaying error messages. It also keeps detailed transaction logs, which tracks hard drive errors. This can help prevent hard disk failures and makes it possible to recover files if the hard drive does fail.

NTFS also allows permissions (such as read, write, and execute) to be set for individual directories and files. It even supports spanning volumes, which allows directories of files to be spread across multiple hard drives. The only reason why you would not want to select NTFS when formatting your hard drive is if you like slow, outdated technology or you need to run an older operating system such as Windows 95 or MS-DOS. Of course, if you are running DOS, there is a good chance you really do like outdated technology.

When a variable has no value, it considered to be null. Having a null value is different than having a value of 0, since 0 is an actual value. However, when used in a boolean test, both null and zero result in a FALSE value. Programmers often use boolean tests to determine whether a variable has been given a value or not.

When a computer or other device is not turned on or connected to other devices, it is said to be "offline." This is the opposite of being "online," when a device can readily communicate with other devices. For example, if you try to print to your printer and you get one of those frustrating errors saying, "The specified printer could not be found," the printer is probably offline. You should check to see if the printer is connected properly and, yes, turned on as well.

Offline can also mean not being connected to the Internet. When you disconnect from your ISP or pull out the Ethernet cable from your computer, your computer is offline. Some programs, such as Web browsers and e-mail programs, have an option to "Work Offline." This option disables the program's network connection, meaning no data can be transmitted to or from the computer. This option was more useful when most people used dial-up connections. They didn't want their computer automatically dialing their ISP whenever a program tried to access the Internet. However, since most people now have "always on" connections such as DSL and cable modems, there usually is no reason to work offline.

Stands for "Object Linking and Embedding." It can be pronounced as "O-L-E," or "Oh-lay!" if you are feeling Spanish. OLE is a framework developed by Microsoft (way back in Windows 3.1) that allows you to take objects from a document in one application and place them in another. For example, OLE may allow you to move an image from a photo-editing program into a word processing document.

The OLE technology was initially created to allow the linking of objects between "compound documents," or documents that support multiple types of data. Microsoft has since developed OLE into a wider standard, known as the Component Object Model (COM). COM is supported by Mac, Unix, and Windows systems, but is primarily used with Microsoft Windows. The COM framework is the foundation of ActiveX, which allows developers to create interactive content for the Web.

In general, when a machine is "online," it is turned on and connected to other devices. For example, when a network printer is online, computers connected to that network can print from it. Other devices, such as scanners, video cameras, audio interfaces, and others are said to be online when they are running and connected to a computer system.

Recently, however, the term "online" usually means being connected to the Internet. The connection can be through a phone line, using a dial-up or DSL modem, a cable line via a cable modem, or through a wireless connection. A computer can also be online via a connection to a computer network. Technically, computers that are on a network are online even if they are not connected to the Internet. But most networks are routed to a T1 line or other Internet connection anyway. When a computer or other device is not online, it is said to be offline.

When a software program is open source, it means the program's source code is freely available to the public. Unlike commercial software, open source programs can be modified and distributed by anyone and are often developed as a community rather than by a single organization. For this reason, the phrase "open source community" is commonly used to describe the developer of open source software development projects.

Since the source code of an open source program can be modified by anyone, it makes sense that the software is also free to download and use. The terms of use are often defined by the GNU General Public License, which serves as the software license agreement (SLA) for many open source programs. Open source software development projects are often funded by donors with an interest in the project, by user donations, or through advertisements. Some developers also generate revenue by selling documentation and help manuals for the software. Other projects are funded by no more than a collective desire of developers to create a great program.

Since open source software is free to use, there is typically no technical support included with the software. Instead, users may need to rely on Web forums and user discussions to report bugs or get answers to their questions. Fortunately, the most popular open source programs have an abundance of helpful resources available on the Web. Some of the most well-known open source projects include the Linux operating system, the Mozilla Firefox Web browser, and the OpenOffice.org productivity suite. Each of these projects have been developed by a community of developers and have gained levels of popularity that rival their commercial counterparts.

OpenGL, or the Open Graphics Library, is a 3D graphics language developed by Silicon Graphics. Before OpenGL was available, software developers had to write unique 3D graphics code for each operating system platform as well as different graphics hardware. However, with OpenGL, developers can create graphics and special effects that will appear nearly identical on any operating system and any hardware that supports OpenGL. This makes it much easier for developers of 3D games and programs to port their software to multiple platforms.

So how exactly does OpenGL work? When programmers write OpenGL code, they specify a set of commands. Each command executes a drawing action or creates a special effect. Using hundreds or even thousands of these OpenGL commands, programmers can create 3D worlds which can include special effects such as texture mapping, transparency (alpha blending), hidden surface removal, antialiasing, fog, and lighting effects. An unlimited amount of viewing and modeling transformations can be applied to the OpenGL objects, giving developers an infinite amount of possibilities.

A set of instructions that tell a computer on how to operate when it is turned on. It sets up a filing system to store files and tells the computer how to display information on a video display. Most PC operating systems are DOS (disc operated system) systems, meaning the instructions are stored on a disc (as opposed to being originally stored in the microprocessors of the computer). Other well-known operating systems include UNIX, Linux, Macintosh, and Windows.

Data that come out of a computer device. For example, information displayed on the monitor, sound from the speakers, and information printed to paper.

A password is a string of characters used for authenticating a user on a computer system. For example, you may have an account on your computer that requires you to log in. In order to successfully access your account, you must provide a valid username and password. This combination is often referred to as a login. While usernames are generally public information, passwords are private to each user.

Most passwords are comprised of several characters, which can typically include letters, numbers, and most symbols, but not spaces. While it is good to choose a password that is easy to remember, you should not make it so simple that others can guess it. The most secure passwords use a combination of letters and numbers and do not contain actual words.

Just like you can paste a note on a sheet of paper, you can paste data into a document on a computer. The paste function can be used to paste copied data into text documents, images, Web browser address fields, and just about any place where you can enter data. However, to paste data, you first need to copy it to the "Clipboard," which is a temporary storage area in your system's memory, or RAM. This is done by first selecting the data you want to copy and then choosing "Copy" from the program's Edit menu.

Once you have data copied to the Clipboard, you can paste it within the same document or within a different document in the same program. You can even paste copied data into a document within a different program. However, you can typically only paste data into a document with the same kind of data. For example, you cannot paste an image into your Web browser's address field or an audio file into image editing program.

To paste a copied piece of data, select "Paste" from the Edit menu in the program you wish to paste the data in. Text documents or programs with text fields will typically paste the data wherever the flashing cursor is. You can also use the keyboard shortcut "Control-V" for Windows or "Command-V" for the Mac OS to paste the data. The reason the "V" key is used is because the "P" key is usually reserved for the "Print" shortcut and "V" is right next to the "C" key, which is used for copying. So it might not be that intuitive at first, but it makes sense when you think about it. =)

For more information about copying and pasting, view the Help Center article.

Personal computer. Generally refers to computers running Windows with a Pentium processor.

Portable Document Format, a format presented by Adobe Acrobat that allows documents to be shared over a variety of operating systems. Documents can contain words and pictures and be formatted to have electronic links to other parts of the document or to places on the web.

A single-user computer containing a central processing unit (CPU) and one or more memory circuits.

A measure of memory or storage capacity and is approximately a thousand terabytes.

The term "pixel" is actually short for "Picture Element." These small little dots are what make up the images on computer displays, whether they are flat-screen (LCD) or tube (CRT) monitors. The screen is divided up into a matrix of thousands or even millions of pixels. Typically, you cannot see the individual pixels, because they are so small. This is a good thing, because most people prefer to look at smooth, clear images rather than blocky, "pixelated" ones. However, if you set your monitor to a low resolution, such as 640x480 and look closely at your screen, you will may be able to see the individual pixels. As you may have guessed, a resolution of 640x480 is comprised of a matrix of 640 by 480 pixels, or 307,200 in all. That's a lot of little dots.

Each pixel can only be one color at a time. However, since they are so small, pixels often blend together to form various shades and blends of colors. The number of colors each pixel can be is determined by the number of bits used to represent it. For example, 8-bit color allows for 2 to the 8th, or 256 colors to be displayed. At this color depth, you may be able to see "graininess," or spotted colors when one color blends to another. However, at 16, 24, and 32-bit color depths, the color blending is smooth and, unless you have some kind of extra-sensory vision capability, you should not see any graininess.

Computer hardware or peripherals that come set up with necessary software so that when attached to a computer, they are recognized by the computer and are ready to use.

A plug-in (also "plugin") is software add-on that adds extra features and capabilities to an application. Typically, plug-ins are stored within a subdirectory of the application folder. When the application is opened, the plug-ins are loaded into the program.

Plug-ins are available for a wide variety of programs, including Web browsers, graphic editors, and audio and video applications. Web browser plug-ins often enable specific types of media to be viewed directly in the browser. Plug-ins for graphics, audio, and video applications may add extra editing tools or filters to the program. While some programs include preinstalled plug-ins created by the developer, many plug-ins are developed by third-party companies.

Stands for "Portable Network Graphic." This format was designed as an alternative to the GIF format (which has been plagued by copyright issues). Like GIFs, PNG files are lossless, meaning they don't lose any detail when they are compressed. They support up to 48-bit color or 16-bit grayscale and typically compress about 5% to 25% better than GIF files. However, they do not support animations like GIFs do. A format similar to PNG, called MNG, is currently under development, and will support animations.

File extension: .PNG

A menu window that opens vertically or horizontally on-screen to display context-related options. Also called drop-down menu or pull-down menu.

A mechanical device for printing a computer's output on paper. There are three major types of printer:

• Dot matrix - creates individual letters, made up of a series of tiny ink dots, by punching a ribbon with the ends of tiny wires. (This type of printer is most often used in industrial settings, such as direct mail for labelling.)

• Ink jet - sprays tiny droplets of ink particles onto paper.

• Laser - uses a beam of light to reproduce the image of each page using a magnetic charge that attracts dry toner that is transferred to paper and sealed with heat.

A precise series of instructions written in a computer language that tells the computer what to do and how to do it. Programs are also called software or applications.

A series of instructions written by a programmer according to a given set of rules or conventions (syntax). High-level programming languages are independent of the device on which the application (or program) will eventually run; low-level languages are specific to each program or platform. Programming language instructions are converted into programs in language specific to a particular machine or operating system (machine language). So that the computer can interpret and carry out the instructions. Some common programming languages are BASIC, C, C++, dBASE, FORTRAN, and Perl.

Python is a programming language commonly used for creating Web applications and software plug-ins. It is designed to be highly readable with an uncluttered visual appearance. Python is similar to other scripting languages like Perl and PHP, but uses English words more frequently and has less punctuation. Programs written in Python can be saved as basic scripts (with a .PY file extension) or compiled programs (with a .PYC extension).

Python is installed on nearly all Unix-based systems, including Mac OS X, and can be run from the terminal. Therefore, if you find out Python is on your computer, don't be scared. It's not a snake, just a programming language.

Random Access Memory, one of two basic types of memory. Portions of programs are stored in RAM when the program is launched so that the program will run faster. Though a PC has a fixed amount of RAM, only portions of it will be accessed by the computer at any given time. Also called memory.

Most images you see on your computer screen are raster graphics. Pictures found on the Web and photos you import from your digital camera are raster graphics. They are made up of grid of pixels, commonly referred to as a bitmap. The larger the image, the more disk space the image file will take up. For example, a 640 x 480 image requires information to be stored for 307,200 pixels, while a 3072 x 2048 image (from a 6.3 Megapixel digital camera) needs to store information for a whopping 6,291,456 pixels.

Since raster graphics need to store so much information, large bitmaps require large file sizes. Fortunately, there are several image compression algorithms that have been developed to help reduce these file sizes. JPEG and GIF are the most common compressed image formats on the Web, but several other types of image compression are available.

Raster graphics can typically be scaled down with no loss of quality, but enlarging a bitmap image causes it to look blocky and "pixelated." For this reason, vector graphics are often used for certain images, such as company logos, which need to be scaled to different sizes.

File extensions: .BMP, .TIF, .GIF, .JPG

Real numbers include all positive and negative numbers. They may be integers (e.g. -12), rational numbers (e.g. 9/10), or irrational numbers, (e.g. 1.4142135...). Numbers with decimal points are also called floating point numbers, since the decimal may also be referred to as a floating point. CPUs can process all types of real numbers, though most processors include a separate floating point unit, or FPU, for processing floating point calculations.

So if there are real numbers, do fake numbers exist? Well, considering that fake numbers, by definition, are not real, the answer is no. However, as many computer nerds know, it is still possible for someone to give you a fake phone number.

This term can describe either how many pixels a monitor can display or how fine a printer can print.

1. Monitors. A small monitor may have a resolution or 640 x 480, which means there are 640 pixels horizontally across the screen and 480 pixels vertically. Some other common monitor resolutions are 800 x 600, 1,024 x 768, and 1,280 x 1,024. The higher the resolution, the more that can be displayed on the screen.

2. Printers. Printer resolution measures how fine a printer can print. This measurement is known as dots per inch, or "dpi." The greater the dpi, the better the image clarity. Scanner resolution is also measured in dpi.

Stands for "Red Green Blue." It refers to the three hues of light (red, green, and blue, for those of you that are a little slow), that can mix together to form any color. When the highest intensity of each color is mixed together, white light is created. When each hue is set to zero intensity, the result is black. TVs and computer monitors use RGB to create the colorful images you see on the screen. In print, however, the 4 colors -- cyan, yellow, magenta, and black (CYMK) -- are used to create color images.

Using the right mouse button to open context-sensitive drop-down menus.

Read-Only Memory, one of two basic types of memory. ROM contains only permanent information put there by the manufacturer. Information in ROM cannot be altered, nor can the memory be dynamically allocated by the computer or its operator.

An electronic device that uses light-sensing equipment to scan paper images such as text, photos, and illustrations and translate the images into signals that the computer can then store, modify, or distribute.

A screenshot, or screen capture, is a picture taken of your computer's desktop. This may include the desktop background, icons of files and folders, and open windows. It may also include whatever is being displayed by currently running programs. Screenshots are and easy way to save something you see on the screen, such as an open window, image, or text article. However, because screenshots are saved in an image format, the text saved in a screenshot will not be editable.

Both the Mac OS and Windows operating systems make it easy to take screenshots. Just use the following keyboard shortcuts to capture the current screen displayed on your computer:

Windows XP:

Print Screen: Saves a screenshot of the entire desktop to the clipboard.
Alt+Print Screen: Saves a screenshot of the active window to the clipboard.

A computer that shares its resources and information with other computers, called clients, on a network.

A service pack is a software package that contains several updates for an application or operating system. Individual updates are typically called software updates or patches. When a software company has developed several updates to a certain program or operating system, the company may release all the updates together in a service pack.

Many Windows users are familiar with service packs because of the popular service pack released for Windows XP, called SP2. Windows XP SP2 not only included typical updates such as bug fixes and security updates, it added new features. Some of the features included new security tools, interface enhancements to Internet Explorer and Outlook Express, and new DirectX technologies. In fact the SP2 service pack for Windows XP was so comprehensive, many newer Windows programs require it in order to run.

Service packs are usually offered as free downloads from the software developer's website. A software update program on your computer may even prompt you to download a service pack when it becomes available. Typically, it is a good idea to download and install new service packs. However, is may also be wise to wait a week or two after the service pack is released to make sure no new bugs or incompatibilities are introduced with the service pack. If you do not have a high-speed Internet connection, you can often purchase a service pack update CD for a small charge.

Software created by people who are willing to sell it at low cost or no cost for the gratification of sharing. It may be freestanding software, or it may add functionality to existing software.

Computer programs; also called applications.

Every computer program is written in a programming language, such as Java, C/C++, or Perl. These programs include anywhere from a few lines to millions of lines of text, called source code.

Source code, often referred to as simply the "source" of a program, contains variable declarations, instructions, functions, loops, and other statements that tell the program how to function. Programmers may also add comments to their source code that explain sections of the code. These comments help other programmers gain at least some idea of what the source code does without requiring hours to decipher it. Comments can be helpful to the original programmer as well if many months or years have gone by since the code was written.

Short programs called scripts can be run directly from the source code using a scripting engine, such as a VBScript or PHP engine. Most large programs, however, require that the source code first be compiled, which translates the code into a language the computer can understand. When changes are made to the source code of these programs, they must be recomplied in order for the changes to take effect in the program.

Small programs may use only one source code file, while larger programs may reference hundreds or even thousands of files. Having multiple source files helps organize the program into different sections. Having one file that contains every variable and function can make it difficult to locate specific sections of the code. Regardless of how many source code files are used to create a program, you will most likely not see any of the original files on your computer. This is because they are all combined into one program file, or application, when they are compiled.

Originating from the name of Hormel's canned meat, "spam" now also refers to junk e-mail or irrelevant postings to a newsgroup or bulletin board. The unsolicited e-mail messages you receive about refinancing your home, reversing aging, and losing those extra pounds are all considered to be spam. Spamming other people is definitely not cool and is one of the most notorious violations of Internet etiquette (or "netiquette"). So if you ever get the urge to let thousands of people know about that hot new guaranteed way to make money on the Internet, please reconsider.

As the name implies, this is software that "spies" on your computer. Nobody likes to be spied on, and your computer doesn't like it either. Spyware can capture information like Web browsing habits, e-mail messages, usernames and passwords, and credit card information. If left unchecked, the software can transmit this data to another person's computer over the Internet.

So how does spyware get on your computer? Just like viruses, spyware can be installed when you open an e-mail attachment containing the malicious software. It can also be installed when you install another program that has a spyware installer attached to it. Because of the insidious nature of spyware, most people don't even know when spyware is on their computer. Fortunately, you can purchase anti-spyware utilities that will search for spyware on your computer and stomp the unwanted software out of your system. A good way to prevent spyware from infecting your computer is to install a security program that lets you know when any program is being installed, so that you can choose to authorize or stop the installation.

SSD is short for "Solid State Drive." An SSD serves the same purpose as a (hard drive|hard drive), but uses flash memory rather than spindle of magnetic disks. It is called a "solid state drive" because it has no moving parts. Since SSDs do not need to move a physical drive head to read data, they can access data faster than hard drives. They also do not need to be defragemented, since their performance does not depend on where data is stored on the disk. Since solid state drives have a number of advantages over hard drives, they have begun to replace hard drives in laptops and other devices.

Devices used to store massive amounts of information so that it can be readily retrieved. Devices include RAIDs, CD-ROMs, DVDs.

A string is a data type used in programming, such as an integer and floating point unit, but is used to represent text rather than numbers. It is comprised of a set of characters that can also contain spaces and numbers. For example, the word "hamburger" and the phrase "I ate 3 hamburgers" are both strings. Even "12345" could be considered a string, if specified correctly. Typically, programmers must enclose strings in quotation marks for the data to recognized as a string and not a number or variable name.

Each spoken language has a general set of rules for how words and sentences should be structured. These rules are collectively known as the language syntax. In computer programming languages, syntax serves the same purpose, defining how declarations, functions, commands, and other statements should be arranged.

Each computer programming language uses a different syntax. Many languages share similar syntax rules, while others have a very unique syntax design. For example, C and Java use a highly similar syntax, while Perl has many characteristics that are not seen in either the C or Java languages.

Regardless of the rules, a program's source code must have the correct syntax in order to compile correctly and be made into a program. In fact, it must have the exact right syntax, or the program will fail to compile and produce a "syntax error." A syntax error can be as simple as a missing parenthesis or a forgotten semicolon at the end of a statement. Even these small errors will keep the source code from compiling.

Fortunately, most software development programs include a debugger, which helps find the exact location of syntax errors within the source code. Imagine a program that has over ten thousand lines of code and a syntax error is caused by one missing semicolon. Finding a needle in a haystack would be preferred over manually locating the error. Needless to say, the debugger makes the debugging process much easier for the programmer.

Whenever you purchase software or hardware for your computer, you should first make sure your computer supports the system requirements. These are the necessary specifications your computer must have in order to use the software or hardware. For example, a computer game may require you computer to have Windows XP or later, a 2.0 GHz processor, 512 MB or RAM, a 64 MB graphics card, and 500 MB or hard drive space. If your computer does not meet all of these requirements, the game will not run very well or might not run at all.

It is just as important to check system requirements for hardware devices. For example, if you buy a printer, it may require either Windows XP or Mac OS X 10.3 or later. It may also require a USB port and 80 MB of available hard drive space. If your computer does not have any USB ports, you will not be able to physically connect the printer. If your machine does not have Windows XP or Mac OS X 10.3 or later, the printer drivers may be incompatible with your operating system. This means you computer will be unable to recognize the printer.

Most hardware and software products have the system requirements printed on the side or bottom of the product packaging. When you are shopping for computer software or hardware, it is a good idea to first find out exactly what your system's specifications are and write them down on a piece of paper. The important information to record includes:

1. Operating System (i.e. Windows XP, SP 2 or Mac OS X 10.3.8)
2. Processor Speed (i.e. Pentium 4, 3.2 GHz or Power PC G5, 2.0 GHz)
3. Memory, a.k.a. RAM (i.e. 512 MB)
4. Graphics Card (i.e. ATI Radeon 9800 w/ 256 MB video memory)
5. Hard Disk Space (i.e. 80 GB available)
6. I/O Ports (i.e. USB, Firewire, Serial, Parallel, SCSI, VGA, DVI ports)

By recording these specifications from your computer, you will be able to make sure your computer supports the products you are buying.

A terabyte is 2 to the 40th power, or 1,099,511,627,776 bytes.

It can be estimated as 10 to the 12th power, or 1,000,000,000,000 bytes. A terabyte is 1,024 gigabytes and precedes the petabyte unit of measurement. While today's consumer hard drives are typically measured in gigabytes, Web servers and file servers may have several terabytes of space. A single 500GB hard drive can also be called a half-terabyte drive.

The prefix "tera" comes from the Greek word meaning "monster." So, if you have a 500GB hard drive, you could say you have half a monsterbyte of disk space. If nothing else, it sure sounds impressive.

For a list of all the different units of measurements, view this Help Center article.

Abbreviation: TB

A thousand gigabytes.

Stands for "Thin Film Transistor." These transistors are used in high-quality flat panel liquid-crystal displays (LCDs). TFT-based displays have a transistor for each pixel on the screen. This allows the electrical current that illuminates the display to be turned on and off at a faster rate, which makes the display brighter and shows motion smoother. LCDs that use TFT technology are called "active-matrix" displays, which are higher-quality than older "passive-matrix" displays. So if you ever see a TFTAMLCD monitor at your local computer store, it is a "thin-film transistor active-matrix liquid crystal display." Basically, it is a high-quality flat screen monitor.

Stands for "Tagged Image File Format." It is a graphics file format created in the 1980s to be the standard image format across multiple computer platforms. The TIFF format can handle color depths ranging from 1-bit to 24-bit. Since the original TIFF standard was introduced, people have been making many small improvements to the format, so there are now around 50 variations of the TIFF format. So much for a universal format. Recently, JPEG has become the most popular universal format, because of its small file size and Internet compatibility.

File extensions: .TIF, .TIFF

As computer users, we have become accustomed to icons that represent files, folders, programs, and other objects on the computer. Many software programs also use icons to represent tools, which are often found in the program's toolbar.

While these icons can save screen space and make the program's interface more attractive, it can sometimes be difficult to tell what all the tool icons mean. While some tool icons are obvious (such as a printer icon to print and a scissors icon to cut a text selection), others are a bit more ambiguous. For this reason, programs often include tooltips that explain what each tool icon represents.

Tooltips are displayed when you roll over an icon with the cursor. It may take a second or two to display the tooltip, but when it does appear, it usually is a small box with a yellow background explaining what the icon represents. For example, in Microsoft Word, when you roll over the disk icon, the tooltip "Save" appears. This means clicking on the disk icon will save your document. In Photoshop, when you roll over the wand icon, the text "Magic Wand Tool (W)" appears. This indicates that clicking the the wand icon or pressing the W key will activate the magic wand selection tool.

Not all programs incorporate tooltips, but most modern programs include them as part of a user-friendly interface. Operating systems also support them in different ways. For example, Mac OS X will show the full text of a long filename when you place the cursor over the filename. Windows includes tooltips for the systray icons and also tells you information about each file and folder you place the cursor over. If you drag your cursor over different icons on your computer, you may find tooltips you never knew were there!

A torrent is a file sent via the BitTorrent protocol. It can be just about any type of file, such as a movie, song, game, or application. During the transmission, the file is incomplete and therefore is referred to as a torrent. Torrent downloads that have been paused or stopped cannot be opened as regular files, since they do not contain all the necessary data. However, they can often be resumed using a BitTorrent client, as long as the file is available from another server.

Torrents are different from regular downloads in that they are usually downloaded from more than one server at a time. The BitTorrent protocol uses multiple computers to transfer a single file, thereby reducing the bandwidth required by each server. When a torrent download is started, the BitTorrent system locates multiple computers with the file and downloads different parts of the file from each computer. Likewise, when sending a torrent, the server may send the file to multiple computers before it reaches the recipient. The result is a lower average bandwidth usage, which speeds up file transfers.

File Extension: .TORRENT

In Internet terminology, a troll is a person who posts offensive or off-topic comments online. These comments are often made to incite arguments or emotional responses from other users. Trolling, as it is called, may take place in Web forums, in blog comment sections, and in social networking websites.

Usernames provide trolls with hidden identities, and therefore a sense of anonymity online. Therefore, trolls often type things they would not actually say in person. The anonymous nature of the Internet gives trolls the capacity to post offensive comments without being held responsible. Fortunately, webmasters can typically delete unwanted posts and remove the accounts of the trolls that invade Web forums and other online communities.

A computer tutorial is an interactive software program created as a learning tool. Tutorials help people learn new skills by using a step-by-step process that ensures the user is following along and comprehending the material. For example, a Web development tutorial may begin with instructions on how to create a basic Web page. This page might only include the words "Welcome to my website" on it and use the minimum HTML required in order for the page to load in a Web browser. Once the user is able to create a working Web page, the tutorial may explain how to add other features, such as styled text, table layouts, and images, to the page. Then the tutorial may provide instructions on how to publish the Web page to the Internet.

Some software tutorials provide testing features to ensure comprehension of the material, while others may be simple walkthroughs of a software program. Tutorials can be used for both school and business purposes and are written for basic, intermediate, and advanced users. Even smart computer programmers use tutorials. Most software development programs include a tutorial for creating a "Hello World!" program, which is the most basic program that can be created with the software. Since tutorials offer a gradual approach to learning, they can be helpful to people at many different skill levels. If a computer programmer can benefit from a tutorial, just about anybody can.

The Undo command is located in the Edit menu of most programs and has the shortcut "Ctrl+Z" (PC) or "Cmd-Z" (Mac). It is used to undo the most recent action performed in a program. Common events that can be undone include typing or deleting text in a word processing program, drawing or moving images in an image editor, and trimming media in a video or audio editing program. By selecting "Undo," most actions can be quickly reversed. Many programs also support "multiple undo," which makes it possible to undo several actions at once.

A very powerful operating system used as the basis of many high-end computer applications.

Uniform Resource Locator.

• The protocol for identifying a document on the Web.
• A Web address (e.g., www.tutorialspoint.com). A URL is unique to each user. See also domain.

A multiple-socket USB connector that allows several USB-compatible devices to be connected to a computer.

A user interface is the means in which a user controls a software program or hardware device. For example, a software interface may include windows, icons, menus, and buttons that allow the user to interact with the program. This is also known as a graphical user interface, or GUI. A hardware interface can be a remote control or a video game controller. It may also refer to the controls on a camcorder, digital camera, or iPod. Most modern user interfaces today are designed using a combination of hardware and software. 

A username is a name that uniquely identifies someone on a computer system. For example, a computer may be setup with multiple accounts, with different usernames for each account. Many websites allow users to choose a username so that they can customize their settings or set up an online account. For example, your bank may allow you to choose a username for accessing your banking information. You may need to choose a username in order to post messages to a certain message board on the Web. E-mail services, such as Hotmail require users to choose a username in order to use the service.

A username is almost always paired with a password. This username/password combination is referred to as a login, and is often required for users to log in to websites. For example, to access your e-mail via the Web, you are required to enter your username and password. Once you have logged in, your username may appear on the screen, but your password is kept secret. By keeping their password private, people can create secure accounts for various websites. Most usernames can contain letters and numbers, but no spaces. When you choose a username for an e-mail account, the part before the "@" is your username.

Utility programs, commonly referred to as just "utilities," are software programs that add functionality to your computer or help your computer perform better. These include antivirus, backup, disk repair, file management, security, and networking programs. Utilities can also be applications such as screensavers, font and icon tools, and desktop enhancements. Some utility programs help keep your computer free from unwanted software such as viruses or spyware, while others add functionality that allows you to customize your desktop and user interface. In general, programs that help make your computer better are considered utilities. And unlike water and electric bills, computer utilities don't send you a bill every month!

Mathematically, a vector is a quantity, defined by both magnitude and direction. For example, a vector could be illustrated by an 1 inch arrow pointing at a 30 degree angle. Another vector may be 2.5 inches and point at a 160 degree angle. In the computer world, vectors are used to define paths in certain types of images, such as EPS files and Adobe Illustrator documents. These images are often called vector graphics since they are comprised of vectors, or paths, instead of dots. Vector graphics can be scaled larger or smaller without losing quality.

In computer science, a vector may refer to a type of one dimensional array. For example, a vector called "fibonacci" that stores the first six values of the Fibonacci sequence would be defined as follows:

fibonacci[0] = 0, fibonacci[1] = 1, fibonacci[2] = 1, fibonacci[3] = 2, fibonacci[4] = 3, fibonacci[5] = 5

Vectors are similar to arrays, but unlike arrays, vectors use their own memory management mechanisms. Arrays are restricted to the memory structure supplied by the programming language they are created in, typically called a stack. Vectors have a more dynamic structure, often referred to as a heap, which gives them greater flexibility in how they use memory. While an array uses a static amount of memory, the memory used by the vector can be increased or decreased as elements are added or removed from the vector.

Unlike JPEGs, GIFs, and BMP images, vector graphics are not made up of a grid of pixels. Instead, vector graphics are comprised of paths, which are defined by a start and end point, along with other points, curves, and angles along the way. A path can be a line, a square, a triangle, or a curvy shape. These paths can be used to create simple drawings or complex diagrams. Paths are even used to define the characters of specific typefaces.

Because vector-based images are not made up of a specific number of dots, they can be scaled to a larger size and not lose any image quality. If you blow up a raster graphic, it will look blocky, or "pixelated." When you blow up a vector graphic, the edges of each object within the graphic stay smooth and clean. This makes vector graphics ideal for logos, which can be small enough to appear on a business card, but can also be scaled to fill a billboard. Common types of vector graphics include Adobe Illustrator, Macromedia Freehand, and EPS files. Many Flash animations also use vector graphics, since they scale better and typically take up less space than bitmap images.

File extensions: .AI, .EPS, .SVG, .DRW

Stands for "Video Graphics Array." It is the standard monitor or display interface used in most PCs. Therefore, if a montior is VGA-compatible, it should work with most new computers. The VGA standard was originally developed by IBM in 1987 and allowed for a display resolution of 640x480 pixels. Since then, many revisions of the standard have been introduced. The most common is Super VGA (SVGA), which allows for resolutions greater than 640x480, such as 800x600 or 1024x768. A standard VGA connection has 15 pins and is shaped like a trapezoid.

An unauthorized piece of computer code attached to a computer program or portions of a computer system that secretly copies itself from one computer to another by shared discs and over telephone and cable lines. It can destroy information stored on the computer, and in extreme cases, can destroy operability. Computers can be protected from viruses if the operator utilizes good virus prevention software and keeps the virus definitions up to date. Most viruses are not programmed to spread themselves. They have to be sent to another computer by e-mail, sharing, or applications.The worm is an exception, because it is programmed to replicate itself by sending copies to other computers listed in the e-mail address book in the computer. There are many kinds of viruses, for example:

• Boot viruses place some of their code in the start-up disk sector to automatically execute when booting. Therefore, when an infected machine boots, the virus loads and runs.

• File viruses attached to program files (files with the extension .exe). When you run the infected program, the virus code executes.

• Macro viruses copy their macros to templates and/or other application document files.

• Trojan Horse is a malicious, security-breaking program that is disguised as something being such as a screen saver or game.

• Worm launches an application that destroys information on your hard drive. It also sends a copy of the virus to everyone in the computer's e-mail address book.

Stands for "Virtual Private Network" (not a successor to the UPN television network). VPN is a network term that most computer users don't need to know, but at least you can impress your friends by talking about it. A virtual private network is "tunneled" through a wide area network WAN such as the Internet. This means the network does not have to be located in one physical location like a LAN. However, by using encryption and other security measures, a VPN can scramble all the data sent through the wide area network, so the network is "virtually" private.

Businesses often use VPNs to communicate across multiple locations. For example, a large company that has offices in several cities may need to send data to the different locations via the Internet. To keep the information secure, the company might set up a VPN with an encrypted connection. This is similar to having a secure intranet over the Internet. On a smaller scale, individual users may have a VPN account with their company, which allows them to connect to their office computer from their home or another location. This is especially helpful for business travelers who need to access office data from their laptops.

A sound format (pronounced wave) used to reproduce sounds on a computer.

Web pages are what make up the World Wide Web. These documents are written in HTML (hypertext markup language) and are translated by your Web browser. Web pages can either be static or dynamic. Static pages show the same content each time they are viewed. Dynamic pages have content that can change each time they are accessed. These pages are typically written in scripting languages such as PHP, Perl, ASP, or JSP. The scripts in the pages run functions on the server that return things like the date and time, and database information. All the information is returned as HTML code, so when the page gets to your browser, all the browser has to do is translate the HTML.

Please note that a Web page is not the same thing as a Web site. A Web site is a collection of pages. A Web page is an individual HTML document. This is a good distinction to know, as most techies have little tolerance for people who mix up the two terms.

Wi-Fi is a wireless networking standard trademarked by the Wi-Fi Alliance. It refers to all networking equipment that is based on one of the IEEE 802.11 standards. Wi-Fi allows computers and other devices to connect to wireless routers and therefore other systems on the network. If the router is connected to the Internet, devices connected to the wireless access point may also have Internet access.

A wiki is a Web site that allows users to add and update content on the site using their own Web browser. This is made possible by Wiki software that runs on the Web server. Wikis end up being created mainly by a collaborative effort of the site visitors. A great example of a large wiki is the Wikipedia, a free encyclopedia in many languages that anyone can edit. The term "wiki" comes from the Hawaiian phrase, "wiki wiki," which means "super fast." I guess if you have thousands of users adding content to a Web site on a regular basis, the site could grow "super fast."

This is the Windows application programming interface (API) for developing 32-bit applications. It has been used for Windows 95, Windows 98, Windows NT, and newer Windows operating systems. This means that if you use Windows 95 or later, you can run 32-bit applications on your computer. Win32 is a term that is important to programmers, but is not crucial for the average user to know. Just know that if you have Windows 95 or later, you can run Win32 applications. If you want to learn more about Win32, including a bunch of technical jargon, you can visit Microsoft's Developer Website for more information.

A window is an area on the screen that displays information for a specific program. This often includes the user interface GUI as well as the program content. Windows are used by most applications as well as the operating system itself. A typical window includes a title bar along the top that describes the contents of the window, followed by a toolbar that contains user interface buttons. Most of the window's remaining area is used to display the content.

Examples:

1. 1. Web Browser windows:
      The top of a typical Web browser window contains a title bar that displays the title of the current page. Below the title is a toolbar with back and forward buttons, an address field, bookmarks, and other navigation buttons. Below the toolbar is the content of the current Web page. The bottom of the window may contain a status bar that displays the page loading status

1. 1. Word Processing windows:
      A window used by a word processing program, such as Microsoft Word, typically includes buttons for page and text formatting, followed by a ruler that defines the document area. Below the ruler is the main page area used for entering text.

1. Operating System windows:
   Windows used by the operating system typically include navigation buttons along the top and shortcuts to folders and other locations on the left side of the window. The rest of the window is used to display icons or lists of files and folders.

Most windows can be opened, closed, resized, minimized, and moved around the screen. The close, minimize, and zoom buttons are located on the title bar (on the right side on Windows and the left side on Macs). Minimizing a window will close the contents of the window, but store a reference to it in the Taskbar (Windows) or the Dock (Mac). Closing a window will make it disappear completely (so you may be asked to save your changes first). To move a window, click on the title bar and drag the window where you want it. To resize a window, either click the Zoom button in the title bar or click the lower right-hand corner and expand or contract the window to the size you want.

Microsoft Windows is the most popular operating system for personal computers. There are several versions of the Windows operating system, including Windows XP (for home users) and Windows 2000 (for professional users). Earlier versions of Windows include Windows 3.1, 95, 98, ME, and NT. All Windows platforms use a graphical user interface (GUI), like the Mac OS, and also offer a command-line interface for typing text commands.

Windows 7 is the seventh version of the Microsoft Windows operating system. It follows Windows Vista and is designed to be a sleeker operating system than its predecessor, with faster performance and fewer compatibility issues. Windows 7 also include several new features, such as multitouch support for touchscreen interfaces, a simple home networking system called "HomeGroup," and an improved Windows Search feature.

Windows 7 is available in three editions in the United States, including Home Premium, Professional, and Ultimate editions. There is also a Home Basic version available in other countries, as well as an Enterprise edition that is only sold to companies through volume licensing.

In the computing world, the term "wireless" can be rather ambiguous, since it may refer to several different wireless technologies. The two most common types of wireless capabilities computers have are Wi-Fi and Bluetooth.

Wi-Fi is the technology used for wireless networking. If your computer has a wireless card, it is most likely Wi-Fi compatible. The wireless card transmits to a wireless router, which is also based on the Wi-Fi standard. Wireless routers are often connected to a network, cable modem, or DSL modem, which provides Internet access to anyone connected to the wireless network.

Bluetooth is the technology often used for wireless keyboards and mice, wireless printing, and wireless cell phone headsets. In order to use a device such as a Bluetooth keyboard or mouse, your computer must be Bluetooth-enabled or have a Bluetooth adapter installed.

Computers may also use other wireless technologies aside from Wi-Fi and Bluetooth. Products such as remote controls and wireless mice may use infrared or other proprietary wireless technologies. Because of the many wireless options available, it is a good idea to check the system requirements of any wireless device you are considering buying.

When most people think of a wizard, they think of an old man with magical powers. This, as with many other computer definitions, has no correlation with the technical term. In computer terminology, a wizard is a part of a program that guides you through certain steps. For example, a wizard in Microsoft Word would help you create and format a new document according to your needs. This is helpful when creating a résumé, outline, invoice, etc. Some other examples of wizards are the Finale 2000 wizard, which helps you create a new music composition with your desired instruments, and the PowerPoint wizard, which helps you set up a presentation using a certain theme.

Basically, a wizard acts as a guide for creating a new document in a software program. Though wizards can be helpful, sometimes they can be more of a hassle than a help for experienced users. Some users would rather just create a new document from scratch, without using a wizard. This is because wizards typically don't offer as much customization as an experienced user may want. Finally, be sure not to confuse a "wizard" with a "template." A template is a pre-formatted document that has already been created, whereas a wizard is a step-by-step guide that helps you create your own document.

A network of servers on the Internet that use hypertext-linked databases and files. It was developed in 1989 by Tim Berners-Lee, a British computer scientist, and is now the primary platform of the Internet. The feature that distinguishes the Web from other Internet applications is its ability to display graphics in addition to text.

What You See Is What You Get. When using most word processors, page layout programs (See desktop publishing), and web page design programs, words and images will be displayed on the monitor as they will look on the printed page or web page.

x86 is the generic name for Intel processors released after the original 8086 processor. These include the 286, 386, 486, and 586 processors. As you can see, the "x" in x86 stands for a range of possible numbers. Technically, x86 is short for 80x86 since the full names of the processors are actually 80286, 80386, 80486, and 80586. The "80" is typically truncated to avoid redundancy.

If a computer's technical specifications state that is based on the x86 architecture, that means it uses an Intel processor (not AMD or PowerPC). Since Intel's x86 processors are backwards compatible, newer x86 processors can run all the programs that older processors could run. However, older processors may not be able to run software that has been optimized for newer x86 processors.

While numbers provide a simple way to distinguish between processor types, they cannot be trademarked. For this reason, Intel's 586 processor is formally known as the Pentium processor. However, software developers still often refer to processors by their number. Of course, what else would you expect from computer nerds?

A yottabyte is the largest unit of measurement for computer data. It consists of 1,208,925,819,614,629,174,706,176 bytes (or 2 to the 80th power). It may also be estimated as 1,000,000,000,000,000,000,000,000 bytes (which is 10 to the 24th power).

Fortunately for those of us finite beings, yottabytes are not used very often. The prefix "Yotta" comes from "Iota," which is the ninth letter of the Greek alphabet. However, it seems more fitting that "yotta" refers to a "lotta" bytes.

For a list of all units of measurement used for computer data, view this Help Center article.

YouTube is a video sharing website owned by Google that allows users to watch other people's videos and publish their own. It allows both professional and amateur users to post videos, which can be viewed by anyone in the world with an Internet connection. Videos uploaded to YouTube are available at YouTube.com and may also be posted on other websites. When a YouTube video finishes playing, the user is presented with a list of related videos that he or she may find interesting. This can make watching YouTube videos an addicting hobby

A zettabyte is 2 to the 70th power, or 1,180,591,620,717,411,303,424 bytes.

It can be estimated as 10 to the 21st power, or 1,000,000,000,000,000,000,000 bytes. A zettabyte is 1,024 exabytes and precedes the yottabyte unit of measurement. Because of the enormous size of a zettabyte, this unit is almost never used. The prefix zetta comes from "Zeta," which is the sixth letter of the Greek alphabet.

For a list of all the different units of measurements, view this Help Center article.

Abbreviation: ZB

Windows users will see this term a lot when looking for files on the Internet. A zip file (.zip) is a "zipped" or compressed file. For example, when you download a file, if the filename looks like this: "filename.zip," you are downloading a zipped file. "Zipping" a file involves compressing one or more items into a smaller archive. A zipped file takes up less hard drive space and takes less time to transfer to another computer. This is why most Windows files that you find on the Internet are compressed.

To use a zipped file, you'll need to unzip it first. PKZIP for DOS, or WinZip for Windows, are some popular programs that can unzip files for you. Fortunately, these programs can be downloaded for free from Web sites like Download.com. Macintosh files are most often "stuffed" into Stuffit files (.sit), which can be "unstuffed" using Aladdin's Stuffit Expander.

The term "Zip" also refers to a product by Iomega. The company makes a removable storage device called a Zip Drive. Depending on the model, these drives can hold 100, 250 or 750 MB Zip disks. They are usually used for backup and for transferring large files to different locations. However, Zip drives are not as fast as hard drives, so it is usually not a good idea to run programs off them.

File extension: .ZIP