Enterprise Admin GROUP :
Members of this group have complete control of all domains in the FOREST By default, this group belongs to the administrators group on all domain controllers in the forest As such this group has full control of the forest, ADD USERS with caution

Domain Admin Group :
Members of this group have complete control of the domain By default, this group is a member of the administrators group on all domain controllers, workstations and member servers at the time they are linked to the domain As such the group has full control in the domain, add users with caution

Enterprise Admin Group :
Members of this group have complete control of all domains in the forest By default, this group belongs to the administrators group on all domain controllers in the forest As such this group has full control of the forest, add users with caution

Domain Admin Group :
Members of this group have complete control of the domain By default, this group is a member of the administrators group on all domain controllers, workstations and member servers at the time they are linked to the domain As such the group has full control in the domain, add users with caution