Glossary term
Backup
An additional, separate copy of important files you would not want to lose.
Reviewed 15 August 2026
Definition
An additional copy of important files, kept somewhere separate from the original, so a loss, deletion or device failure doesn't mean losing them for good.
In plain English
A backup is a copy you keep on purpose, not just whatever happens to be saved automatically in one place — if the only copy is always connected to the original, it may not really be protected.
Common confusion
Cloud sync isn't always the same as a backup — a deleted or damaged file can sync everywhere just as easily as a good one.