Redis handles data persistence using a process called snapshotting. Snapshotting is a process where the in-memory data is written to disk in a consistent form, allowing for data recovery in the event of a system failure.
For example, Redis can be configured to create a snapshot of the data every hour. This snapshot is written to a file on disk, and can be used to restore the data in the event of a system failure. Additionally, Redis can be configured to create a snapshot after a certain number of writes, or after a certain amount of time.