Glossary 177
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 hard disks. Compare

disc

. See also

hard disk

.
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

.
double-click—To press and release the pointing device’s
primary button rapidly twice without moving the pointing
device. In the Windows® operating system, this refers to the
pointing device’s left button, unless otherwise stated.
download—(1) In communications, to receive a file from
another computer through a modem or network. (2) To send
font data from the computer to a printer. See also

upload

.
drag—To hold down the mouse button while moving the pointer
to drag a selected object. In the Windows® operating
system, this refers to the left mouse button, unless otherwise
stated.
driver—See

device driver

.
DVD—An individual digital versatile (or video) disc. See also

DVD-ROM

.
DVD-ROM (Digital Versatile [or Video] Disc Read-Only
Memory)—A very high-capacity storage medium that uses
laser optics for reading data. Each DVD-ROM can hold as
much data as several CD-ROMs. Compare

CD-ROM

.
Eemulation—A technique in which a device or program imitates
another device or program.
enable—To turn on a computer option. See also

disable

.