Network operating system

Network operating system
Network Operating System also referred to as the Dialoguer,is the software that runs on a server and enables the server to manage data, users, groups, security, applications, and other networking functions.
The network operating system is designed to allow shared file and printer access among multiple computers in a network, typically a local area network (LAN), a private network or to other networks.
The most popular network operating systems are Microsoft Windows Server 2003, Microsoft Windows Server 2008, UNIX, Linux, Mac OS X, Novell NetWare, and BSD.
http://en.wikipedia.org/wiki/Network_operating_system