backup

operating system (Sometimes "back up" when used as a verb) A

spare copy of a file, file system or other resource for use in

the event of failure or loss of the original.

The term is most commonly used to refer to a copy of all the

files on a computer's disks which is made periodically and

kept on magnetic tape or other removable medium (also called

a "dump").

This essential precaution is neglected by most new computer

users until the first time they experience a disk crash or

accidentally delete the only copy of the file they have been

working on for the last six months.

Ideally the backup copies should be kept at a different site

or in a fire safe since, though your hardware may be insured

against fire, the data on it is almost certainly neither

insured nor easily replaced.

See also differential backup, incremental backup, fullbackup. Compare archive.

(2003-06-22)