You can't have two domains on the same server 2003 machine, since it has to manage a single domain. However, you can have many domains in a server 2003 forest or a series of trees, which are managed by a forest controller.
And, a single server 2003 can manage multiple domains.
child and parent domains
There are four domain functional levels for Windows Server 2003: Windows 2000 mixed Windows 2000 native Windows Server 2003 interim Windows Server 2003
Windows Server 2003 interimSupported domain controllers: Windows NT 4.0, Windows Server 2003Supported features: There are no domain-wide features activated at this level. All domains in a forest are automatically raised to this level when the forest level increases to interim. This mode is only used when you upgrade domain controllers in Windows NT 4.0 domains to Windows Server 2003 domain controllers.
The difference between the server and domains is fairly simple. The server is the system on which the entire functions rest, and the domains are pages within that system. Imagine the server as a neighborhood and domains as houses.
one needs to make trust between the domains. please check below the different types of the trusts One-way trust One domain allows access to users on another domain, but the other domain does not allow access to users on the first domain. Two-way trust Two domains allow access to users on both domains. Trusting domain The domain that allows access to users from a trusted domain. Trusted domain The domain that is trusted; whose users have access to the trusting domain. Transitive trust A trust that can extend beyond two domains to other trusted domains in the forest. Intransitive trust A one way trust that does not extend beyond two domains. Explicit trust A trust that an admin creates. It is not transitive and is one way only. Cross-link trust An explicit trust between domains in different trees or in the same tree when a descendant/ancestor (child/parent) relationship does not exist between the two domains. Shortcut Joins two domains in different trees, transitive, one- or two-way Forest Applies to the entire forest. Transitive, one- or two-way Realm Can be transitive or nontransitive, one- or two-way External Connect to other forests or non-AD domains. Nontransitive, one- or two-way. Windows 2000 Server supports two-way transitive and one-way intransitive trusts. Administrators can create shortcuts. Windows Server 2003 the forest root trust. This trust can be used to connect Windows Server 2003 forests if they are operating at the 2003 forest functional level. Authentication across this type of trust is Kerberos based (as opposed to NTLM). Forest trusts are transitive for all the domains in the trusted forests. Forest trusts, however, are not transitive.
Domain functional level of all domains at Windows 2000 Server or higherDomain controller with Active Directory running Windows Server 2003Stand-alone server (with Windows 2003 Server, .Net Framework 2.0, CD drive)Microsoft Exchange Server 2007
The two access controls can be set up with "Authentication and Access Control. These are available in the Windows Server 2003 folders.
trust is used for different domains we can log-in to different users this known as trust trust divided 3 types 1 one way incoming 2 one way outgoing 3 two way trust
The windows Server 2003 will function as a router for either subnetwork
WINS server works only at level of LAN and uses a list of IP addresses with corresponding names, it does not allow you to use domains. DNS is almost the same thing but it allows you to span the network in domains and work with them.
Because server 2008 is more updated than server 2003.
To accomplish this, you can use a feature called (depending on your server software) Virtual Domains, Virtual Hosts, Co-Domains, Addon Domains, or something to that effect.