I think you guys will be able to help me. I am confused why universal group are in Windows 2003 AD. We can perform all our tasks by using global and domain local group. Global groups do not increase replication traffic and by global group , it is easy to assign permissions to another domain users. But what special task can be done by universal group? Universal group will add more replication traffic between domains that is it. What else they can do? Is any one know advantages of using Universal group in single or multi domain environment?