224 Glossary

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double-density diskette — A 3.5-inch diskette that can hold up to 720 KB of information (half the capacity of a high-density diskette). See also diskette, high-density diskette.

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 cursor 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.

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

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

executable file — A computer program that is ready to run. Application programs and batch files are examples of executable files. Names of executable files usually end with a .bat or .exe extension.

expansion device — A device that connects to a computer to expand its capabilities. Other names for an expansion device are port expander, port replicator, docking station, or network adapter.

extension — See file extension. external device — See device.

file — A collection of related information, saved on disk with a unique name. A file may be a program, information used by a program, or a document. See also document.

file allocation table (FAT) — The section of a disk that keeps track of the location of files stored on the disk.

file name — A set of characters that uniquely identifies a file within a particular folder. It consists of two parts: the actual name and the file name extension. See also file extension.