Servers use realms to partition protected resources; each partition can have its own authentication scheme and/or authorization database. Realms are used only for basic and digest authentication. After a client successfully authenticates, the authentication is valid for all resources in a given realm. For a detailed description of realms, see RFC 2617 at http://www.ietf.org.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)