But if someone edits or deletes content that's subject to the policy, a copy is saved to a secure location where it's retained while the policy is in effect. 'When content is subject to a retention policy, people can continue to edit and work with the content as if nothing's changed because the content is retained in place, in its original location. Setting retention policy serves similar function to litigation hold in that it keeps copies of all purged items for the duration of the retention period. It simply moves what currently exists into the Archive database based on the age you set.
Archiving (O365 or on-premise Exchange) doesn't do that.
