Glossary 117
CPU—See

Central Processing Unit (CPU).

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

cache.

cursor—An onscreen symbol (usually a flashing vertical line)
that indicates the position where characters will appear
when you enter data.
Ddefault—The setting selected by a program when the user does
not specify an alternative setting.
device—A component attached to the tablet. Devices may be
external (outside the tablet’s case) or internal (inside the
tablet’s case). Printers, disk drives, and modems are
examples of devices.
device driver—A program (called a “driver”) that permits the
tablet to communicate with a device.
Direct Current (DC)—The type of power usually supplied by
batteries. DC flows in one direction. Compare

Alternating

Current (AC).

disable—To turn the option off. See also

enable

.
disk drive—The device that reads and writes information and
programs on external media or hard disk. It rotates the disk
at high speed past one or more read/write heads.
document—Any file created with an application and, if saved
to disk, given a name by which it can be retrieved. See also

file

.
download—(1) In communications, to receive a file from
another source through a network. (2) To send font data from
the tablet to a printer. See also

upload

.
drag—To touch and hold an item for a moment and then,
without lifting your finger, move the item until you reach the
target position.
driver—See

device driver

.
Eemulation—A technique in which a device or program imitates
another device or program.