Authenticated Users and Domain Users Members
If I understand if you have one Active Domain then Authenticated Users group and Domain Users group is the same thing.
If You have Multiple AD Domain, then Authenticated Users group is forest wide but Domain Users group is domain limited.
in both case though the difference is If I am not wrong the authenticated Users group can have Users and Computers as its members but Domain Users Group can have only Users but not computers
I would like an AD Expert to confirm or correct me if I am wrong.