Administrator and Administrators Group difference Windows Server 2008 and 2008 R2

Question

Sorry if this question is not unique. 1) Is there any difference in permissions between a user in Administrators GROUP and USER Administrator. 2) If they differ, are this differences the same for LOCAL Admins user and group and
for Domain Admins and Group

Answer 1

The functional difference between local Administrator and the local Administrators Group are very little if any. Entities in Administrators Group have the same rights on that machine as the Administrator User.

Domain Admins gains its rights on the local machine through having Domain Admins be a member of the local Administrators Group. Remove Domain Admins from that group, and Domain Admins will be able to do a lot less on that machine than they could otherwise.