Hello company_san, A volume is dynamic until at least one Replay has been taken of that volume.  After a Replay has been taken of a volume, it becomes Replay enabled. A Replication volume is one that is being Replicated to another Storage Center.  Please let us know if you have any other questions.
Can you edit a volume type after a volume is created or do you have to do it during the creation process? I select advance when creating the volume and am not seeing it.
Volume Type