A domain is a logical grouping of network servers and other computers that share common security and user-account information. Within domains, administrators create one user account for each user. Users then log on to the domain, not to individual servers in the domain.
The term domain does not refer to a single location or specific type of network configuration. Computers in a single domain can share physical proximity on a small LAN or can be located in different parts of the world. They communicate over any of various physical connections, such as dial-up lines, ISDN, fiber, Ethernet, token ring, frame relay, satellite, and leased lines.
The domain structure provides the following advantages for maintaining a secure network:
Network users can connect to multiple servers by logging on to a single network.
The user needs only one domain user account and password to use network resources.
A centralized view of the entire network from any workstation on the network provides the ability to track and manage information on users, groups, and resources in a distributed network. This single point of administration for multiple servers simplifies the management of a Windows NT Server – based network.
For detailed information about domains, see "Managing Windows NT Server Domains" in the Microsoft Windows NT Server 4.0 Concepts and Planning Guide.