Glossary · IT & systems
Backup
A spare copy so your data doesn't get lost.
A backup is a spare copy of your data, kept in a separate place. If something goes wrong with the original, through a fault, a mistake or an attack, you can fall back on the copy and restore your data.
Its importance only becomes clear at the worst possible moment. Anyone without a recent copy when a system fails or ransomwareExtortion software that locks your files until you pay. strikes can lose years of data. A good backup is the cheapest insurance against that kind of disaster.
Having a copy is not enough; it also has to work. So test regularly whether you can actually restore a backup, and keep at least one copy separate from your systems. A backup that sits next to the original goes down with it in the same attack.
