What is snapshot policy?

Snapshots give you the ability to retrieve earlier versions of files or folders in case of unwanted changes or deletion of data. Snapshots can be configured so that one is made every hour, every day or on a particular day of the week, in addition to manually.

Logically, a snapshot is similar to a copy of the underlying file structure and all its files and content. Technically, to save space and to ensure that the entire snapshot is made at the exact same moment in time, the snapshot is merely a time stamp with pointers to data. The content is then automatically copied on write (copy-on-write). Thus, snapshots should only be used as intended, not as a backup.