backup definition operating system
("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 commonly refers to a copy of the files on a computer's disks
, 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 backup software
, differential backup
, incremental backup
, full backup. Compare archive
, source code management