Allows to store business-critical data in WORM (Write Once Read Many) state
This makes the data undeletable and unmodifiable for the time period specified
Even the administrator of the storage account cannot delete the data

This feature needs to be configured at the container level
All attempt that are made to modify the data in the retention period is logged

Retention Approaches

Time-based Retention
Set policy to retain data for a fixed time
Even after the retention period the data cannot be modified but it can be deleted

Legal Hold
Useful if not sure how long the data needs to be stored
We need to create a tag with metadata to remember why data is kept on hold
As long as a tag exist the data in the container cannot be deleted/ modified