Network Operating System (NOS)
The network operating system (NOS) consists of a family of programs that run in networked computers. Some programs provide the ability to share files, printers, and other devices across the network. As previously mentioned, computers that share their resources are called servers; computers that use the resources on other computers are called clients. It is common to run client and server software on the same computer. This enables one user to access the resources on another computer while coworkers make use of resources on your computer.
Networking software can be a special program added on to the computer, such as Artisoft's LANtastic or Novell's NetWare, or it can be an integral part of an operating system such as Microsoft's Windows 95 or Windows 98, Windows NT, or Windows 2000.