This is one of the specialized operating system which is designed mainly for servers. We can say this as a complete operating system with file, task and job management and there are some earlier products it was a separate component that ran under OS like LAN server required OS/2 and LANtastic required DOS. UNIX, LINUX and Solaris are common network operating system and designed for use in stand-alone servers. Such operating systems also include web servers, directory services, messaging systems, network management and multiprotocol routing facilities. Some of the example of network operating systems are Novell NetWare, Microsoft Windows NT, Microsoft Windows 2000, Microsoft Windows XP, Sun Solaris, Linux, etc.
Window NT combine the computer and network operating system in one. It configure a system to provide server function and resource to a network and its workstation also provide the client functions of the network. It operates on the domain model which is a collection of computers that share a common database and security policy. As we know each domain has a unique name and within that one server may be entitle as the primary domain controller (PDC). This server maintain the directory services and authenticate any user to log on and can be implemented in various ways by using account and security. There are four domain choice single-domain which is a single server going to maintain the security and accounts database. Single-master in which a person designated as a master and network may have several domains and master is maintaining the user-accounts database. Multiple-master model is designed for very large organization which include several domain and account database is also maintained by more than one server. Complete-trust is a type of domain in which there is no master all the domains are there and trust each other.
Novell Netware is one of the most popular NOSs which offers client software which run on the top of the computer because of its design NetWare NOS consist of server client application in which client application is designed to run on a many different client operating systems and the server application can be accessed by the users from different computer running MS-DOS, Microsoft windows, Unix or AppleTalk. Once installing Netware on any client workstation user can take full advantage of the resources provided by NetWare server some of them are NetWare file services are a part of NDS database. NDS provides single-point logon for users which allow user to view network resources in the same way. Lets take an example to understand this a window client can map a logical drive to any NetWare file server which behave like a logical drive on their computer which is like a any other drive. It provide extensive security including Logon security, trustee rights and directory and file attributes.