Backup

A separate copy of data, systems or settings kept so they can be restored if the original is lost, damaged, encrypted by ransomware or accidentally deleted.

A backup can cover individual files, entire servers, cloud services such as Microsoft 365, or full computer images. Good backups run automatically, are monitored for failures, and are kept for long enough that you can go back to a point before a problem started.

Backups are often the difference between a bad day and a business-ending event. If ransomware encrypts your files, a reliable backup may allow you to recover without negotiating with criminals. A common misunderstanding is that cloud services automatically back everything up. Providers such as Microsoft keep their platforms running, but recovering your deleted or corrupted data over the long term is generally your responsibility.

Practical tip: know what is backed up, where it goes, how long it is kept and how quickly it can be restored. Test restores regularly, protect backup systems with separate credentials and multi-factor authentication, and keep at least one copy offline or immutable.