The network domain is a notion that defines a set of D3 Servers and Clients on a network. On Windows, it matches the Windows domain. Because of this one-to-one relationship, a network domain in D3 terminology is simply called a domain.
The domain is the basic space seen by a D3 application. It defines the resources an application can see and use. Access to the resources on the domain are controlled by the Windows Domain Controller. It is possible to access one domain from another by specifying an explicit domain name, as detailed in MDS.
See Also
D3 File System Interface Server Configuration