Brian Cryer's Glossary of IT Terms with Links

Backup

Backup

1. A recovery system or means to recover in the event of a disaster.

2. To take a copy of files (directories or data) so that these can be restored later if needed. Backups should always be taken regularly to protect against accidental deletion of files or hardware failure.

Many applications generate a backup file as they work. For example most work processors can be configured to generate a backup file of the document they are working on, allowing the previous version to be recovered if necessary. However this type of backup will not protect against hardware failure, if the disk fails then you loose your original and the backup.

A good backup scheme will ensure that files are copied to a separate medium (such as cd or tape) and physically moved to a different area, ideally to a different site. Moving a backup (or a copy of a backup) to an offsite location is referred to as an "offsite backup", and the advantage of maintaining an "offsite backup" is that it allows files to be recovered in the event of a disaster such as a fire that may destroy the entire building.

3. The copy of a file (or set of files or data) that has been taken. A backup may therefore be the copy of a file or it may refer to a disk, cd or tape that contains files (or data) that have been backed up.