Temporary memory areas that help your computer or peripheral avoid bottlenecks. For example, the exchange of data to and from a computer's RAM is a slow process compared to the speed of a CPU. (It's measured in microseconds, but it adds up.) The "primary cache" is a small but fast RAM reservoir often built into the CPU that stores data recently accessed by the CPU. The secondary cache is larger and is contained outside the CPU.
Web browsers use a caching system to store recently accessed files in RAM, on the hard drive or both. When you click on the browser's back button, it reads the page out of the cache, rather than requesting and downloading the page from the server again.
Local storage of recently viewed web pages for faster retrieval of information. Browsers store the most recently viewed web pages on the user's hard drive. When the user requests to see the content (text or images) again, instead of retrieving it from the web, the browser will search for it in a local folder on the viewer's system called the cache. The result is faster page loads for the viewer. This process causes underreporting of the number of times a viewer actually saw a web page or ad.
A device that stores an electrical charge.
Compact Disc-Recordable. CD-R disks can be written to ("burned") one time by a CD-R drive, and they can be read by normal CD-ROM drives. The disks can not be erased.
Compact Disc-Read Only Memory disk, the storage medium used in CD-ROM drives. Identical to audio compact discs (though produced with greater precision), the 5-inch disks store more than 600 megabytes of data. See CD-ROM drive.
A read-only disk drive that reads CD-ROM disks. The drives are similar to audio CD players, but are capable of accessing data anywhere on the disk, not just at the beginning of tracks, and in many cases operate at higher rotational speeds resulting in higher data transfer rates. CD-ROM data transfer rates never compare to those of hard disk drives. See related article on CD-ROM drives.
Colloquially, "CPU" is used interchangeably with "microprocessor," "processor" and sometimes just "chip" to mean the integrated circuit that does all the number crunching -- the serious work -- in a computer. When you talk about a fast computer, you're talking mostly about the CPU. When you hear of Pentium and PowerPC chips, you're hearing about CPUs. Technically speaking, the CPU and microprocessor are not the same; the CPU is part of the microprocessor. If the distinction ever makes a real difference to the public, we'll let you know. See related articles on the CPU/microprocessor.
A forum that allows two or more online users to converse by typing to each other. Chat has migrated from bulletin boards and online services to the World Wide Web, and is increasingly utilizing audio and video. See a related article about Internet Relay Chat.
A unit of measure for data, larger than bits, bytes and nibbles put together.... OK, we made up "chomp," but the other ones are real. Can you believe it?
Complex Instruction-Set Computing. This is a CPU design that sacrifices some speed in order to have a complete set of built-in instructions on the chip. CISC chips excel at complex and non-repetitive tasks like database work.
Installation of operating system software during which a hard disk is erased clean before the system software is installed. This is the simplest way to insure that the installation goes smoothly.
A computer workstation on a network, or a software application on such a computer, that can request and download information from a server. Web browsers and most e-mail programs are client applications.
A measurement of how fast the CPU can process information, often gauged in megahertz (MHz). The higher the speed, the faster the CPU and the better the performance.
A processor that assists the CPU in performing a specialized function. It is also called an accelerator. A math co-processor, or FPU (floating point unit), handles complicated arithmetic. CPUs that don't have a math co-processor can do floating point calculations, but not nearly as quickly.
The number of colors a video adapter can display at once. See related article on monitors.
The separation of a color graphic into the four basic ink colors used in conventional printing: yellow, cyan, magenta and black. Printing presses print these four colors on the paper sequentially from separate inked plates. Some desktop publishing applications can separate the four colors and produce "camera-ready" documents that can be output to a printer.
Data or file compression is the coding of data to save storage space or transmission time. Coding (or encoding) can squeeze the data into less space, providing that the data can later be decoded to return it to its original state. For example, it takes less space to store this:
"10101000110101[insert 75 zeroes here]11011010010"
than this:
"10101000110101000000000000000000
0000000000000000000000000000000000
0000000000000000000000011011010010."
Certain types of modems perform compression encoding and decoding to speed transmission when connected to other, similarly equipped modems.
A window on Macintosh and Microsoft's Windows 95 operating system software that presents options for controlling values and functions of the system, and sometimes other software.
The chip or device that transmits instructions to a peripheral.
Information stored on a user's computer by a Web Browser at the request of software at a Web site. Web sites use cookies to recognize users who have previously visited them. The next time the user accesses that site, the information in the cookie is sent back to the user so the information displayed can vary depending on the user’s preferences.
CPU
The central processing unit.
Originally referred to a head crash, although the word is now used to describe any sudden failure of a computer or system, be it software- or hardware-related, catastrophic or curable with a simple reboot. "Bomb" is often used interchangeably with "crash."
Cathode ray tube, the glass part of a computer monitor -- including the screen and the guts that project images on it. "CRT" is often used interchangeably with "monitor."
A Cascading Style Sheet (CSS) provides the ability to separate the layout and styles of a web page from the data or information. Styles such as fonts, font sizes, margins, can be specified in one place, then the Web pages feed off this one master list, with the styles cascading throughout the page or an entire site.
Well on its way to becoming the most overused prefix of the decade, though "virtual" is providing stiff competition.
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