domain controller DC
a domain controller (DC) is a server that responds to security authentication requests (logging in, checking permissions, etc.) within the Windows Server domain.
Domain Controller
The DNS Server Role and the active directory is not installed till the adds service is started on the server 2008.if the service is not started(one needs to check the option under roles of the server)the active directory installation wont happen.this feature is only in 2008 not in 2003.The active directory works as service in 2008
Forest root domain
No, you do not. You only install Active Directory if the system is going to be a domain controller. If it is a member server or a standalone server Active Directory should not be installed.
Default Domain Policy and Default Domain Controller Policy
Active Directory service is used to store information about the network resources across a domain and also centralize the network.
offline defragmentation
domain name service
Active Directory Domain Services. in server 2008 AD work as a service
Administrative domain.
system state backup for non Dcsystem state + AD files for DCOn a Windows domain controller, the System State data encompasses the system startup files, system registry, COM+ class registration database, File Replication service (the SYSVOL directory), Certificate Services database (if it is installed), Domain Name System (if it is installed), Cluster service (if it is installed) and Active Directory. The DNS data includes DNS zone information that is Active Directory-integrated. The Cluster service data includes any registry checkpoints and the quorum log, which contains the most recent cluster database information. Active Directory includes the following files:Ntds.dit . The Active Directory database.Edb.chk . The checkpoint file.Edb*.log . The transaction logs; each 10 megabytes (MB) in size.Res1.log and Res2.log . Reserved transaction logs.
the centralized directory database in the domain model is NTDS.DIT(directory information tree) but for the local sstem not connected to domain is SAM