As defined by Microsoft, in Active Directoryserver 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.
See also Active Directory.