Active Directory Windows 2000 stores information about all of its resources in what is called the Active Directory. This is the directory service model that allows all of the resources to be available to the users. The Active directory is replicated to all domain controllers in a domain.
All domain controllers have a writable copy of the database.
Active Directory is stored in a file called NTDS.dit. The largest component of Active Directory is the forest. The forest consists of a group of trees that trust each other. Next we have the tree. A tree is a set of domains that are connected together by transitive trusts.