Snapshots and backups: which one when

A snapshot is a point in time of the disk, kept on the same machine. It is taken in seconds and rolled back in seconds, which makes it the thing to do right before a risky change: an upgrade, a config edit, a migration. It is not a backup — it lives and dies with the server's disk, and you can keep only a couple.

A backup is a copy of the whole server on our separate backup server. With the backup add-on, one is taken every night and kept for a week, and you can take extra ones yourself. You restore any of them from the server page; the server is rebuilt from the copy with the same address.

Rule of thumb: snapshot before you change something; backups so that a broken disk, a bad script or a mistake a week ago is not the end of the story.