The DNS is a server which masks your public IP, whereas DHCP is a server which automatically assigns a Dynamic IP adress
I wouldn't exactly say "mask". Dns just puts a nice easy name to an ip, like Google, or hotmail etc... DHCP just gives out ip addresses.
in Active Directory server roles, computers that function as servers within a domain can have one of two roles: member server or domain controller. A member server is a computer that runs an operating system in the Windows 2000 Server family or the Windows Server 2003 family, belongs to a domain, and is not a domain controller. Member servers typically function as the following types of servers: file servers, application servers, database servers, Web servers, certificate servers, firewalls and remote-access servers.
Domain controller
Domain controller
Domain Name Servers hold IP address to host name and host name to IP address mappings. For each domain there is usually a primary and secondary Domain Name Server.
window 2000 server domain controller and windows 2000 server member server in domain.
IP addresses, DNS database, Name Servers, and the Domain Name Space.
Windows Server 2003, and Windows NT 4.0
IP addresses, DNS database, Name Servers, and the Domain Name Space.
Active Directory
Domain Controller it is Microsoft Windows Server 2000/2003 directory server that provides access controls over users, accounts, groups, computers and other network resources. Domain Controller authenticate users and maintains directory services and the security database for a domain.
The Netlogon subkey stores information for the Net Logon service. The Net Logon service verifies logon requests, and it registers, authenticates, and locates domain controllers. Also, to maintain backward compatibility, Net Logon manages replication of the user account database to back up domain controllers running Windows NT 4.0 and earlier. For Windows 2000, Net Logon manages replication only when replication involves servers running Windows NT 4.0 and earlier. Net Logon for Windows 2000 does not manage replication between two servers running Windows 2000.
In Windows Server 2011 it is called Active Directory.