Short answer: A snapshot is a point-in-time image of a VPS disk that you take manually, usually before a risky change; a backup is an automatic, scheduled copy that rotates and is often stored separately. Both are full-disk images; neither replaces copies kept with another provider.
Snapshot vs backup explained
Snapshots are quick to create and restore and can be used to clone a server. They often live on the same storage system as the server and may be billed per GB.
Automatic backups run daily or weekly, keep several generations and are designed for recovery after mistakes or failures. Many providers charge 10–20% of the plan price for them; some include them free.
For important data, also keep application-level backups (database dumps, files) at a different provider or in object storage.
See it in the data
Frequently asked questions
Are snapshots backups?
Not on their own: they are manual and often stored with the server. Use scheduled backups plus off-site copies.