Glossary
Backup
The copy of your data that lets you recover everything after a failure or a mistake. A backup never tested is only a hope.
A backup is a regular copy of your data, kept elsewhere, that lets you restart after a failure, a handling mistake or an intrusion. Every serious tool makes some, but for its own needs, on its own terms.
The two questions that matter: how many hours of work can you accept losing (frequency follows), and above all: have you ever tested it? Our rule: nothing gets lost, and a backup is tested by an actual restore. Many teams find out at the worst moment that theirs does not restore.