shankar Ganesh said:
Kindly give the full concept of active directory in server.
An overly simplified description would be:
A computer network directory is a hierarchical data store of objects and
their attributes. An object can be a shared resource, a user account, a
domain, an application, a security policy or any other entity in a network.
A directory service is both the source of the data store and the services
that makes that data available to users on the network.
Directory services make the physical aspects of the network transparent
to the user. Active Directory Services (ADS) also protects network objects
from unauthorized access and replicates objects across the network.
ADS provides centralized administration. Active Directory Services
provides a single point for administrative purposes (example: a universal
administrator with directory wide access).
more info:
http://www.microsoft.com/windows2000/technologies/directory/ad/default.asp