Glossary

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.