Backups and snapshots are accessible from the Backups tab in the Store dashboard.
Backups are scheduled automatically by the system. They're created daily after 01:00, UTC time. Daily backups are kept for 7 days. Weekly backups, created on Sunday after 01:00, are kept for 5 weeks.
Snapshots are on-demand backups that you should create every time you plan to do major changes on your store. They allow you to easily revert your changes in case something goes wrong.
You can create a snapshot by clicking the button Create Snapshot in the Backups tab. Snapshots are kept for 7 days.