262 Glossary

color palette — A set of specified colors that establishes the colors that can be displayed on the screen at a particular time.

compatibility — The extent to which computers, programs, or devices can work together harmoniously, using the same commands, formats, or language as another.

configuration — (1) The collection of components that make up a single computer system. (2) How parts of the system are set up (that is, configured).

controller — A device that controls the transfer of data from a computer to a peripheral device and vice versa. For example, disk drives, monitors, keyboards, and printers all require controllers.

CPU — See central processing unit (CPU).

CPU cache — A section of very fast memory residing between the CPU and the computer’s main memory that temporarily stores data and instructions the CPU will need to execute commands and programs. See also cache, L1 cache, L2 cache.

cursor — A symbol that indicates the current position on the screen. The shape of the cursor varies, depending on the program you’re using and what you’re doing.

D

default — The setting selected by a program when the user does

 

 

not specify an alternative setting.

 

device — A component attached to the computer. Devices may be

 

external (outside the computer’s case) or internal (inside the

 

computer’s case). Printers, disk drives, and modems are examples

 

of devices.

 

device driver — A program (called a “driver”) that permits a

 

computer to communicate with a device.

 

dialog box — An on-screen window displayed by the operating

 

system or a program giving a direction or requesting input from

 

the user.

 

direct current (DC) — The type of power usually supplied by

 

batteries. DC flows in one direction. Compare alternating current

 

(AC).