Security groups (used to grant permissions). (Can be used as an email distribution list).
Distribution groups
Can create authorizations.
Group areas
Global group to organize network access for users with similar requirements. Membership in Global Groups is restricted, and may be nested with other groups.
Group area of local domains is used to grant domain permissions to domain resources that are in the same domain.
Groups of the local domain cannot be nested into other groups.
Universal group area is hereby granted permissions for similar resources in several domains
All user accounts and groups can be members.
Important: Security groups with a universal group area are only available if all domain controllers run under W2K.
