In a Microsoft Windows 2000 network, the Active Directory(tm) provides the structure and functions for organizing, managing, and controlling network resources.
Whereas in the legacy operating system NT 4.0, network management required the use of numerous different administrative tools,
the Active Directory provides a centralized database and a common interface (the Microsoft Management Console or MMC).
The Active Directory provides a whole new way of accomplishing administrative tasks and allows for far more granularity in delegating administrative authority.
It also provides compatibility with other Lightweight Directory Protocol (LDAP) 
directory services, allowing for interoperability in a variety of network environments.
This module will teach you the role and structure of Active Directory. Mastering this material is not difficult, but it will take time. At the end of this module, you will be able to: