Laptop User Manual

Glossary

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 — An on-screen symbol (usually a flashing vertical line) that

indicates the position where characters will appear when you enter

data.

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).

direct memory access (DMA) — A dedicated channel, bypassing the

CPU, that enables direct data transfer between memory and a

device.

directory — See folder.

disable — To turn a computer option off. See also enable.

disc — A round, flat piece of material, designed to be read from and

written to by optical (laser) technology, and used in the production

of optical discs, such as CDs and DVDs. Compare disk.

disk — A round, flat piece of material that can be magnetically

influenced to hold information in digital form, and used in the

production of magnetic disks, such as diskettes and hard disks.

Compare disc. See also diskette, hard disk.

disk drive — The device that reads and writes information and programs

on a diskette or hard disk. It rotates the disk at high speed past one or