The s

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*cable*		A collection of bundled wires with a connector on each end. Cables electrically connect a computer to its peripherals. Some cables are flat, called ribbon cables.
cache		A special block of fast memory used for temporary storage of data for quick retrieval. Compare buffer. (Think of a buffer as a temporary holding place between two devices, and a cache as a temporary holding place for one device.) See "disk cache" and "RAM cache."
CAD		(cad) Computer Aided Design. Using microcomputer-based software to produce architectural and mechanical engineering drawings. Usually requires a fast computer with powerful graphics and mathematical capability, a large screen, and lots of memory.
CAD-CAM		When CAD computers are connected to CAM equipment; you design the part on a CAD system, the CAD system tells the CAM system what to make, the CAM computer directs the milling machine as it makes the part.
CAM		Computer Aided Manufacturing. Using microcomputers to control manufacturing equipment such as milling machines.
Caps Lock key		A toggle key on the keyboard that makes all letters type uppercase, but does not affect the numeral, punctuation, or function keys.
card		See expansion card.Cards are smaller than boards.
cardbus		An addendum to the Personal Computer Memory Card International Association (PCMCIA) PC Card standard that allows PC Cards and their hosts to use 32-bit bus mastering. This standard specifies that CardBus peripherals will be hot-swappable and support plug and play; however, new cards won't work in old slots.
caret		The ^ symbol. Frequently used to represent the Control (Ctrl) key on the keyboard. For example, ^C means to hold down the Control key while you type the letter C. Also used to represent exponential notation on printers or fonts that can't show superscript. For example, 12^2 = 144.
carriage return		A printer command to move the printhead to the beginning of the line. Usually goes with a line feed. Named after the carriage return lever on a typewriter.
case sensitive		Making a distinction between uppercase and lowercase. DOS commands and filenames are not case sensitive. Passwords frequently are case sensitive.
CD		Compact Disc. The plastic, optically-read medium used in CD-ROM drives. Note the spelling of disc.
CD-ROM		Compact Disc Read Only Memory. An information (data) storage device that uses compact disc technology. CD's can store over 650MB, but most cannot be written to, hence the appellation "read only".
CD-ROM drive		The device that reads CD-ROM discs.
Centronics port		The most common parallel interface in microcomputing, used especially for printing. The company Centronics is no longer in existence.
CGA		Color Graphics Adapter. IBM's first microcomputer color standard. CGA allowed a maximum of four colors at a resolution of 320 x 200 or two colors at 640 x 200.
CGI		Common Gateway Interface. A standard for running external programs from a World-Wide Web HTTP server. What is returned from the CGI program is based on what was requested, and this information can be accessed and returned to the user in many different ways.
character		Any letter, punctuation mark, or one of about a hundred special shapes called graphics characters, especially if generated by the character generator chip. See ASCII.
character generator		A chip or circuitry that takes a byte that represents a character and sends the bitmap of it to the monitor. Usually able to send only a limited number of characters.
character mode		See text mode.
chassis		The metal frame to which the electronic components of the computer (such as the system board, power supply, and drive bays) are attached. The chassis goes inside the part you see, which is variously called the lid, enclosure, or system unit cover.
checksum		A number calculated from a block of data, used to verify the integrity of that data. For example, a modem could send a block of data and include the number of 1's that occur in the block. The receiving modem could count the number of 1's it receives and compare its own number with the transmitted number. If the numbers are the same, the transmission was probably OK.
chip		The square or rectangular piece of plastic or metal that contains an integrated circuit. Most chips have thin metal legs that connect to the integrated circuit inside. See integrated circuit.
chip set		A collection of integrated circuits that are designed to be used together for some specific purpose.
circuit board		An arrangement of electronic components wired together on a thin sheet of non-conductive material. The wiring is almost always printed on and within the card. Also the system board.
circuit card		A small circuit board, especially an expansion card.
CISC		Complex Instruction Set Computer. Refers to microprocessor architectures with many instructions built in so as to have as many functions as possible on one chip. The benefit is easier assembly language programming. The Intel 80x86 family are CISC chips. Compare RISC.
clamping voltage		The voltage at which a surge protector begins to surge-protect. A good surge protector has a clamping voltage of about 135 volts. Damage to equipment can occur as low as 160 volts.
click		To press and release the mouse button without moving the mouse. To click on something means to position the pointer on an object on the screen, then click.
client		Between slave and peer. A system that is able to operate independently, but has some degree of dependence on another system. Frequently refers to computers on a local area network. Compare peer, slave.
clock		The oscillator that generates the timing pulses that coordinate the parts of and enable the flow of data within a digital device. Also a circuit powered by battery that keeps track of the date and time for human and various system requirements.
clock doubling		Refers to a system whose internal CPU clock runs twice as fast as the clock for the rest of the computer. This has the effect of increasing computing speed without the expense of high-speed hardware.
clock speed		The frequency at which a clock oscillates. In microcomputers, measured in MHz. The faster the clock, the faster the computer can compute.
CMOS		Complementary Metal-Oxide Semiconductor. A material from which some IC's are made. CMOS chips are fast, consume very little power, and cost a lot. CMOS chips store setup information used by the boot program. The setup program is often called the CMOS Setup program.
coaxial cable		A type of cable used in networks. Has a single conductor in the center surrounded by a thick plastic sheath, which in turn is covered by a braided wire mesh shielding, then a final protective layer of plastic. Also called coax. (coe-axe)
code		Anything in a computer language, either on paper or in the computer itself. Also to write instructions in a computer language.
codec		coder-decoder. Used primarily with Internet phone and video conferencing products, this software compresses digitized data and decompresses it at the other end, allowing for faster data transfer and less delays.
code page		A table (written and electronic) that relates the characters in a program to the keys on a keyboard and to the characters that display on the screen. Particularly useful with foreign alphabets.
cold boot		Switching a computer completely off, then switching it back on again. See warm boot.
collision		When two signals on a network interfere with each other.
collision avoidance		The ability of a node on a network to detect that a collision will not happen if the node transmits a signal. See Token Ring.
collision detection		The ability to tell when a collision in a network has occurred in order to know that retransmission is necessary.
.COM		A type of executable program identified by the .com extension on the filename. COM files are always shorter than 64K. Also (without the leading period) a name to identify a serial port.
COM port		One of up to four serial ports allowable in DOS. Identified by number: COM1, COM2, COM3, COM4. Normally only two COM ports can be used at one time, and they must have consecutive numbers.
command		An instruction, usually typed from the keyboard or chosen from a menu, that tells the computer or the program it is running to do something.
command interpreter		The operating system program that controls the shell. The command interpreter for DOS is COMMAND.COM. The command interpreter for Windows is WIN.COM.
command line		The line on the screen, in DOS, where the cursor is. Where you enter DOS commands. Also the text of the command itself.
command line interface		A way for humans to communicate with a computer by means of a command line. Once you know the commands, this interface can be very efficient. Compare GUI.
command prompt		See DOS prompt. An indicator at the beginning of the command line that indicates that the system is ready to receive a command.
COMMAND.COM		The program that carries out DOS commands. The generic term for this program is command interpreter.
communications software		See terminal software.
compact disc		A plastic disk that uses optical technology to store information. Usually called a CD. Note the spelling of disc.
composite		Refers to a type of color monitor in which the color signals all come in on the same line and are separated electronically inside the monitor. Compare RGB.
compression		Any scheme for recording data with fewer bits. For example, stating how many times something occurs can be shorter than stating each occurrence. It is shorter to say print a million white pixels than to say "print white pixel number one, print white pixel number two . . ."
computer		Any device that takes input, applies rules to (processes) the input, and outputs the result. Typical analog computers may use a mechanical system of cams, gears, and levers to produce output in the form of the position of a mechanism, or a system of variable electrical circuits to produce output as a trace on an oscilloscope. A slide rule is a simple analog computer. At the most fundamental level, all digital computers use discrete electrical signals (bits ) as input and output, and Boolean algebra to process the input. A calculator is a simple digital computer.
CON		DOS's device name for console, the monitor and keyboard.
condition		To completely discharge, then fully recharge a NiCad battery in order to remove its memory, thus increasing its useful service life. Also the use of special equipment to make a phone line work better for digital transmission.
CONFIG.SYS		A text file that determines certain settings and device drivers within the DOS operating environment. When you boot the computer system, MS-DOS looks for this file in the root directory of the disk you are booting from, and configures itself according to the settings in this file.
configuration		The way in which a computer and its peripherals are connected as a system, especially the firmware settings of its internal components, such as memory size and video mode. Also the basic settings of how software is set up. For example, Windows is configured with a driver for the printer you use. Configuration is often used interchangeably with "setup."
console		The part of a computer that interfaces with humans: the keyboard and monitor. Originally, the console was the control unit (a keyboard and monitor in a single enclosure) to a large computer.
contention		In networking, when two stations try to use a network resource simultaneously, especially when they send a signal on the same line simultaneously.
context sensitive		Help that varies depending where you are in a program. See help. For example, if you have the File Menu down and press the help command, help about the file menu would appear.
control key		Usually shown as Ctrl. One of three shift keys on a computer keyboard. The meaning of a key pressed while the Control key is held down may depend on what software is running. See control key combination.
control key combination		Pressing and releasing a key while holding down the Ctrl key. Shown, for example, as Ctrl+C. Control key combinations frequently send commands rather than characters. For example, Ctrl+C frequently sends a "break" command.
control panel		A small utility, seen as a window with mouse-operated controls, that affects the appearance or operation of a GUI. Control panels are usually kept together in a group called Control Panels.
controller		A device that enables another device to communicate with a computer, especially the expansion card on the bottom of a disk drive.
conventional memory		Random access memory (RAM) with addresses below 640KB; DOS can directly address only conventional memory.
cookie		An Internet mechanism that lets site developers place information on the client's (your) computer for later use. For example, some shopping cart technologies allow you to return to shopping at a later time. What this means is that a "cookie" containing your order numbers is placed on your computer for the site's computer to retrieve when you return.
cookie file		The file (usually in your browser's directory structure) where cookies are kept.
coprocessor		A chip whose function is to support the CPU by performing certain functions for it. A math coprocessor, for example, performs floating point calculations for the CPU much faster than the CPU itself can.
core memory		An old term for main memory. From when RAM was physical frameworks of donut-shaped magnets called cores.
cow		A domestic bovine-like animal, regardless of sex or age. Gateway 2000's mascot.
CPU		Central Processing Unit. In a microcomputer, a processor on an IC chip (called a microprocessor) that serves as the heart of the computer. It interprets and carries out instructions, performs numeric computations, and controls the peripherals connected to it. Often the entire system unit is called the CPU.
CPU clock		A clock circuit, or oscillator, contained in the CPU chip that controls the speed at which it operates. Traditionally the CPU and system clocks operate at the same frequency, however some CPU chips operate at a multiple of the system frequency.
CPU clock speed		The frequency (measured in MHz) at which the internal CPU clock operates. Systems with higher CPU clock speeds perform many tasks faster and require more power than identical systems with slower CPU clocks. For example, other things being equal, a system that operates at 33 MHz is faster than a system that operates at 25 MHz. Systems with clock-doubling technology have a CPU clock speed twice as fast as the system clock.
crash		When a computer system fails suddenly. Same as hang, "lock up," and "bomb." Usually requires rebooting the computer. Crashes almost always originate in software or firmware and very seldom cause actual damage to the hardware.
CRLF		Carriage Return with Line Feed. A printer command that moves the printhead to the left (the beginning of the line) while the paper advances one line, thus enabling the printer to print a new line of text.
CRT		Cathode Ray Tube. Generally used to refer to the entire monitor.
CSA		Canadian Standards Association. They test product safety.
CSTN		Color Super Twisted Nematic. A color passive matrix screen technology developed by Sharp Electronics. An enhancement to the twisted nematic (TN) technology for LCD displays that twists the molecules greater than 90 degrees (from 180 to 270 degrees) for better contrast. STN is a passive matrix display.
Ctrl		The label on the Control key.
CUA		Common User Access. The policy of using the same command for a given function in all software. This makes the software easier to learn and use because you only have to learn one set of commands. Windows has a set of CUA guidelines which many Windows programs follow. For example, Alt+F4 always means close this window.
cursor		The indicator on the screen that shows where the next character will appear when you type. In DOS, the cursor is usually a blinking underline character. In Windows, it is usually a blinking vertical bar. Cursor is derived from the Latin word meaning to run, and has nothing to do with one's choice of vocabulary when the computer malfunctions.

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