Read only domain controller (RODC) is a feature of Windows Server 2008 Operating System. RODC is a read only copy of Active Directory database and it can be deployed in a remote branch office where physical security cannot be guaranteed. RODC provides more improved security and faster log on time for the branch office.

Active Directory Recycle bin is a feature of Windows Server 2008 AD. It helps to restore accidentally deleted Active Directory objects without using a backed up AD database, rebooting domain controller or restarting any services.

Adding one group as a member of another group is called 'group nesting'. This will help for easy administration and reduced replication traffic.

Domains, Organizational Units, trees and forests are logical components of Active Directory.

The reverse lookup zone file is used to hold PTR (commonly called pointer) records. PTR records are found only in reverse lookup zones and provide an IP address to name resolution method. In other words, the client passes an IP address to the DNS server, and the DNS server replies with the hostname. PTR records are commonly used for security purposes..