Domain name queries are handled by the DNS Servers. The most popular DNS server software is BIND 9.
A DNS servers that is setup with to preform recursive queries or an SQL server
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.
window 2000 server domain controller and windows 2000 server member server in domain.
DNS Servers
DNS servers
A forwarder is a Domain Name System (DNS) server on a network used to forward DNS queries for external DNS names to DNS servers outside of that network. You can also forward queries according to specific domain names using conditional forwarders.A DNS server on a network is designated as a forwarder by having the other DNS servers in the network forward the queries they cannot resolve locally to that DNS server. By using a forwarder, you can manage name resolution for names outside of your network, such as names on the Internet, and improve the efficiency of name resolution for the computers in your network. For more information about forwarders and conditional forwarders
establishes a set of name server records in the DNS servers of the parent domain, indicating the IP addresses of DNS servers that are authoritative for the domain.
Member servers are computers that act as servers within a domain. It is a computer that runs in the operating system of the windows 2000 server family. Member server is in a domain but is not a domain controller. It can work as file server, application server, web server etc. Some of the key functions of member server are email management, faxing, file storage, web services etc.
Whenever mail servers talk to each other, they look for MX records at the destination's DNS. When a DNS server is setup for a domain and that domain has mail capabilities, their DNS server will have at least one MX record to denote which server handles mail. The root DNS servers for the internet denote the addresses for the SOA (start of authority) DNS servers for a particular domain.
The server which is domain controller only that server has AD installed on it others are just member servers which does not have AD on them but has only windows 2003 OS.So you can make changes in ad related servers or DCs only. You can install AD on member server that is the only thing you can do on member server related with Ad
The servers which is live in the domain and helping in performing any operation is a production server and if the server is down there is loss in workforce/organixzations production. DHCP server,printer server,dns server,file server sharepoint,sms etc.
If you are not hosting on your own servers, you would need to contact your domain host.