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Glossary
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C
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C, and C ++. A programming language developed at Bell Laboratories. C is a general-purpose language and can manipulate the internal workings of a computer as an assembly language can. C++ is an improved version of the C language that adds object-oriented extensions.
cache. A place in memory where the computer can temporarily store data to avoid accessing the hard or floppy disk drive. Often called a RAM cache.
CAV. Acronym for Component Analog Video.
CCITT. Abbreviation of Comite Consultatif International Telephonique et Telegraphique, an organization that sets international communications standards. CCITT, now known as ITU (the parent organization) has defined many important standards for data communications.
CDMA. Short for Co de- Division Multiple Access, a digital cellular technology that uses spread-spectrum techniques. Unlike competing systems, such as GSM, that use Time-division multiplexing (TDM), CDMA does not assign a specific frequency to each user. Instead, every channel uses the full available spectrum. Individual conversations are encoded with a pseudo-random digital sequence. CDMA is a military technology first used during World War II by the English allies to foil German attempts at jamming transmissions. The allies decided to transmit over several frequencies, instead of one, making it difficult for the Germans to pick up the complete signal. Because Qualcomm Inc. created communications chips for CDMA technology, it was privvy to the classified information. Once the information became public, Qualcomm claimed patents on the technology and became the first to commercialize it.
CDPD. Short for Cellular Digital Packet Data, a data transmission technology developed for use on cellular phone frequencies. CDPD uses unused cellular channels (in the 800- to 900-MHz range) to transmit data in packets. This technology offers data transfer rates of up to 19.2 Kbps, quicker call set up, and better error correction than using modems on an analog cellular channel.
CD-ROM. Compact Disc-Read Only Memory. Often used to describe a CD-ROM drive, which is a special disk drive that reads only compact discs.
central processing unit. Sometimes called the CPU or the processor. A chip in personal computers that control everything in the computer.
CG. Acronym for Character Generator.
CGI. The Common Gateway Interface (CGI) is a method of allowing a World Wide Web link to refer to a program rather than a static Web page.
chain mail. Think of electronic chain mail as messages that promise good luck if you forward them to others and bad luck if you do not.
character set. A character that appears on your computer screen, which can be a number, letter or symbol, is the graphical interpretation of a number. For a computer to know what characters to display, it refers to a database that associates a single character with each number. This database is called a character set.
CISSP. (Certification for Information System Security Professional) A certification reflecting the qualifications of information systems security practitioners. The CISSP examination consists of 250 multiple choice questions, covering topics such as Access Control Systems, Cryptography, and Security Management Practices, and is administered by the International Information Systems Security Certification Consortium or (ISC)2 (www.isc2.org). The (ISC)2 promotes the CISSP as an aid to evaluating personnel performing information security functions. The certification was first available in 1989.
client. A computer that accesses shared network resources provided by another computer, called a server.
client-access licenses. Licenses for network applications specifying how many users can use the application.
clip. Small QuickTime Movie. Also used to mean a segment of a larger movie, defined by an in point and an outpoint usually containing a single scene or take.
CMX. The most commonly used editing computer. The EDL is loaded into it and it executes the edits and effects by controlling all of the required video machines. Actually it may not control all of them. Certain operatios may need to be done manually. Most editing computers use the CMX language, which has become industry standard.
color burst. A portion of the composite video signal used for decoding its color information. Burst is several c ycles of 3.58 MHz pulses recorded during the horizontal blanking interval and used to establish phase relationships for determining the hue. the color oscillator of a color television receiver is phase locked to the color burst.
color correction. A process in which the coloring in a video image is altered by electronic means.
color subcarrier. The 3.58 MHz signal which carries color information. This signal is superimposed on the luminance level. Amplitude of the color sub-carrier represents saturation and phase angle represents hue.
compositing. Combining two or more video or electronic images into a single frame or display.
compression. To squeeze a file so that it takes up less space.
CompuServe. CompuServe is a commercial subscription-based on-line service that acts as a computing network, Internet access provider, bulletin board and more.
computer. A programmable machine which has two principal characteristics: (1) It responds to a specific set of instructions in a well-defined manner. (2) It can execute a prerecorded list of instructions (a program).
computer virus. A computer virus is a self-replicating program containing code that explicitly copies itself and can "infect" other programs by modifying them or their environment such that a call to an infected program implies a call to a (possibly evolved) copy of the virus.
contrast. The range of light and dark values in a picture or the ratio between the maximum and the minimum brightness values.
control strip. The Control Strip is a control panel originally designed for the PowerBooks and introduced to all Mac OS computers in Mac OS 7.5.3. It allows easy control of such tasks as file sharing, monitor settings, sound levels and AppleTalk activity. By default, it takes the form of a strip of icons at the bottom left hand corner of the screen.
controller. Portion of the QuickTime Movie Playback window with which you interactively control the direction and rate of playback.
control track. The portion along the length of a video tape on which sync control information is placed and used to control the playback of the video signal.
conventional memory. On IBM PC and compatible computers, the first 640 kilobytes of memory (RAM).
convergence. 1. The beam-position accuracy of the red, green, and blue beams of a color monitor or projector. color systems require exact accuracy of beams, both for position and speed, to properly produce the desired colors from their phosphors. 2. The adjustment of the red, green, and blue electron beams in a monitor or video projector to align the red, green and blue images.
cookie. The cookie is a text file saved in your browser's directory or folder and stored in RAM while your browser is running. Most of the information in a cookie is pretty mundane stuff, but some Web sites use cookies to store personal preferences.
CORBA. Short for Common Object Request Broker Architecture, an architecture that enables pieces of programs, called objects, to communicate with one another regardless of what programming language they were written in or what operating system they're running on. CORBA was developed by an industry consortium known as the Object Management Group (OMG). There are several implementations of CORBA, the most widely used being IBM's SOM and DSOM architectures. CORBA has also been embraced by Netscape as part of its Netscape ONE (Open Network Environment) platform. Two competing models are Microsoft's COM and DCOM and Sun Microsystems' RMI.
CPU. Central processing unit. The computational and control unit of a computer; the device that interprets and executes instructions. The CPU or microprocessor, in the case of a microcomputer, has the ability to fetch, decode, and execute instructions and to transfer information to and from other resources over the computers main data-transfer path, the bus. The CPU is the chip that functions as the "brain" of a computer.
cracker. Originally, the term "hacker" described any amateur computer programmer who discovered ways to make software run more efficiently. In a broader sense, the term "hacker" describes anyone who writes computer programs, modifies computer hardware, or tinkers with computers or electronic devices for fun. Recently, the popular definition of "hacker" has changed to describe a person who maliciously breaks into computer networks with the intent to snoop, steal data, or tamper with files. Legitimate hackers resent the association of the term "hacker" with criminal activity. They use the term "cracker" to describe someone who breaks into networks.
crash. When the computer or a network suddenly stops working.
cross color. A defect characteristic of NTSC composite video that manifests itself as spurious rainbow patterns on highly textured objects like the one found on a striped shirt or tweed jacket. Cross-color defect is attributed to the make-up of the signal which mixes the high luminance and chrominance information in the same composite baseband spectrum. Johnny Carson used to wear ties with designs specifically designed to create this effect.
cross luminance. A defect characteristic of NTSC composite video that appears as a dot pattern crawiling up on or hanging on the edges of color areas. This is a result of the signal structure where the color information leaks into the luminance signal. Also referred to as dot crawl.
cross-platform. A term used to indicate that a piece of software can run on any operating system platform.
CRC. Cyclical redundancy check. An error-detection technique used to verify the accuracy of data transmission.
CRT. An acronym that stands for Cathode Ray Tube. CRTs appear in computer monitors and TV screens.
CSS. Short for Cascading Style Sheets, a new feature being added to HTML that gives both Web site developers and users more control over how pages are displayed. With CSS, designers and users can create style sheets that define how different elements, such as headers and links, appear. These style sheets can then be applied to any Web page. The term cascading derives from the fact that multiple style sheets can be applied to the same Web page. CSS was developed by the W3C. The specification is still evolving and is not fully supported by any current Web browsers.
current directory. The directory that you are working in at any moment is the current directory and is the one from which DOS stores and retrieves files. Any directory on a hard or floppy disk can be the current directory, but only one directory can be the current directory at any given time.
cyberspace. The electronic ether where on-line communications takes place. Coined by William Gibson in his novel Neuromancer, it's the mental locale where folks with modems meet, somewhere out there in the nether world.
