Glossary

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.