2 Answers
Hi Michael,
https://aws.amazon.com/blogs/storage/protecting-data-with-amazon-s3-object-lock/
This blog might help.
A legal hold doesn’t have an expiration date/retention period. It will stay in effect until it is removed. You would use a legal hold when you don’t know how long you need the lock for. The hold can be removed by users with appropriate permission.
The compliance lock involves specifying a retention period. Once set, no-one can delete the objects, including root user.
I believe this is e.g. for EU-GDPR: Data has to be stored and then after a period to be deleted. Except there is reason to store further: e.g. criminal investigation, lawsuit, or other reason to avoid deletion of evidence.