CA - (See "certificate authority")

 

CA certificate - certificate that identifies a certificate authority.

 

cache {cash} - small amount of fast memory holding recently-accessed data, designed to speed up subsequent access to the same data. (see "RAM cache")

 

cache {cash} - collection of Web page copies stored on your computer's hard disk or in its random-access memory (RAM). The browser accumulates these copies as you browse the Web. When you click a link or type a URL to fetch a particular Web page for which the cache already contains a copy, the browser compares the cached copy to the original. If there have been no changes, the browser uses the cached copy rather than refetching the original, saving processing and download time.

 

cache files - Web pages, graphics and other files that are down-loaded into your computer when you browse an Internet site. These temporarily-stored files allow the browser to reload the page quickly, if you access the page again. Most browsers clear the cache on a regular basis.

 

CAD {cad} [Computer Aided Design] - CAD uses computer graphics to construct highly detailed drawings.

 

card - (see "expansion card")

 

carrier - Continuous frequency capable of being either modulated or impressed with another information-carrying signal.

 

CCD (see "charged coupled device")

 

CD recorder (burner) - A compact disc drive that can be used to produce discs readable in other CD-ROM drives and audio CD players.

 

CD-R [Compact Disc Recordable] - A recordable CD-ROM which can be read by normal CD-ROM drives; data can only be recorded once onto a CD-R, and cannot be changed.

 

CD-ROM {see-dee rom} [compact disc–read only memory] - A fform of data storage that uses laser optics rather than magnetic means for reading data.

 

CD-RW [CD-ReWritable] - A CD-ROM that can be written, erased, and rewritten by the user. CD-RW discs usually will only play on Multi-Read CD-ROM drives.

 

Celeron® {sel-ur-on} - brand of processors from Intel for the basic PC market that have the same architecture as the Pentium II processor, but less built-in, high-speed cache memory.

 

central processing unit [CPU] - Part of a computer that controls its operation. Units within the CPU perform arithmetic and logical operations and decode and execute instructions. In personal computers, the entire CPU is on a single chip.

 

certificate - digital equivalent of an ID card. A certificate specifies the name of an individual, company, or other entity and certifies that a public key, which is included in the certificate, belongs to that entity. When you digitally sign a message or other data, the digital signature for that message is created with the aid of the private key that corresponds to the public key in your certificate. A certificate is issued and digitally signed by a certificate authority (CA). A certificate's validity can be verified by checking the CA's digital signature. Also called digital ID, digital passport, public-key certificate, X.509 certificate, and security certificate.

 

certificate authority (CA) - service that issues a certificate after verifying the identity of the person or entity the certificate is intended to identify. A CA also renews and revokes certificates and generates a list of revoked certificates at regular intervals. CAs can be independent vendors (such as the CAs listed at Netscape's Client Certificates).

 

CGI [Common Gateway Interface] - A way of interfacing computer programs with Internet servers, so that a server can offer interactive sites instead of just static text and images.

 

chad - The perforated edge strips on printer paper after they have been separated from the printed portion.

 

charged coupled device (CCD) - The electronic version of film for a digital camera, it is the chip used to record image information. Light hits the CCD when a photo is taken and then the analog CCD converts the information to digital. This is one of the two main recording devices used in digital cameras.

 

chat - To have a real-time conversation online.

 

chat mode - A mode in which users can type messages back and forth to each other, which are transmitted in real time.

 

chat room - A real-time electronic forum; a virtual room where visitors can meet others and share ideas on a particular subject.

 

chip - A miniaturized electronic circuit mass-produced on a tiny chip or wafer of silicon. Goes well with DIP.

 

chrome - [from automotive slang via wargaming] Showy features added to attract users, but contributing little or nothing to the power of a system. Distinguished from bells and whistles by the fact that the latter are usually added to gratify developers' own desires for featurefulness. Often used as a term of contempt.

 

clean boot - Starting the computer and only loading the main part of the operating system.

 

click - What the user does when he presses a button on a mouse or other pointing device.

 

click and drag - To use a mouse or other pointing device to grab an item on the computer screen and move it to another location. To click and drag, point to an item, click the pointer and hold the button down while dragging the item to the desired location; then release the button.

 

client - Software (such as browser software) that sends requests to and receives information from a server, which is usually running on a different computer. A computer on which client software runs is also described as a client.

 

client/server - An architecture in which one computer can get information from another. The client is the computer that asks for access to data, software, or services. The server supplies the requested data or services. (compare "peer-to-peer network")

 

clock speed - The speed at which a computer performs basic operations, given in MegaHertz; determined by the frequency of vibration of a quartz crystal that sends pulses to the CPU.

 

clone - A computer that can run all IBM-type software and has interchangeable hardware.

 

cluster - The smallest unit of disk space that DOS can allocate to a file which consists of one or more contiguous sectors.

 

CMOS {SEE-moss} [Complementary Metal Oxide Semi-conductor] - Chipset used to store setup information regarding video, floppy and hard drives; current date and time; battery supported to run when PC is turned off.

 

cold boot - A boot from power off. (compare "warm boot")

 

command.com - The DOS and Windows 9x command interpreter.

 

command interpreter - A program that reads textual commands from the user or from a file and executes them. When a PC is started, the command interpreter is loaded into memory.

 

communications port [COM port] - A connector for a communi-cations interface, usually, a serial port.

 

compact flash - A digital memory card with the largest physical size and storage capacity. About the size of a matchbook and weighing about half an ounce, these cards come with a capacity as high as 2 GB. They are better for use with high-megapixel digital cameras. There are also versions that store at a high-speed rate, which is helpful for shooting several pictures in succession.

 

compact disc [CD] - (Not "disk"). A high-capacity, optical storage device that can store multimedia information.

 

compatible - Computer that will run all IBM-type software, but which may contain non-standard hardware components.

 

COM port - (see "communications port")

 

compressed file - File that has been compacted by a special program so that it uses less disk space. (.ZIP, LZH, etc.)

 

computer - A machine that can be programmed to thoroughly confuse and irritate normal persons. The physical components that make up a computer are known as "hardware."

 

config.sys - A file found in the root directory that is used to load DOS drivers and configure the system.

 

conventional encryption - A form of encryption in which sender and receiver share with each other a secret key to decrypt messages sent between them. Conventional encryption, also called private key encryption, is different from public key encryption in which both sender and receiver have the public key, but each has a private key which is not shared.

 

conventional memory - The first 640 KB of memory in a computer in which all software must run.

 

cookie - A cookie is a set of data that a website server gives to a browser the first time the user visits the site and that is updated with each return visit. The remote server saves the information the cookie contains about the user and the user's browser does the same, as a text file.

 

co-processor - (see "floating point processor")

 

corrupted file - A file so damaged (by a virus, or by software or hardware failure) that the computer is unable to read it.

 

Core 2 - a brand name that refers to Intel's x86 64-bit microprocessors (with the eighth-generation microarchitecture, named Core architecture) targeted at the consumer and business markets (except the servers) above Pentium Dual-Core. The Core 2 marked a relegation of the Intel's Pentium brand to a lower-end market, and a reunification of Intel's notebook and desktop brand names, previously divided into the Pentium M and Pentium 4 lines.

 

The Core 2 brand for desktop, laptop, and workstation PCs was introduced on 27 July 2006 comprising Duo (dual-core), Quad (quad-core), and Extreme (dual- or quad-core CPUs with higher speeds and unlocked multiplier) branches.

 

cps {sea-pea-ess} [characters per second] - A transfer rate estimated from the bit rate (bps) and length of each character.

 

CPU {sea-pea-ewe} - (see "central processing unit")

 

crash - A sudden, usually drastic failure of a computer system.

 

crash and burn - A spectacular computer crash, in the mode of the conclusion of the car-chase scene in the movie Bullitt and many subsequent imitators.

 

crosslinked files - An error in the file allocation table that results when two files lay claim to the same cluster on a disk.

 

CTRL key - Key that gives alternate meanings to other keys, thus expanding the keyboard's capability. The CTRL key is held down like a Shift key, and another key is pressed.

 

cup holder - The tray of a CD-ROM (or DVD) drive, or by extension the drive itself. So called because of a common tech support legend about the idiot who called to complain that the cup holder on his computer broke.

 

cursor - The short blinking line that appears underneath the space where the next character is to be typed.

 

cyberspace - The electronic universe of information available through the Internet where time and space have no meaning.