NOS (Network Operating System) is designed to run on a server in a client or server network environment. it turns a PC into a network server. some example of of NOSs are:
Microsoft Windows NT/2000 Server/Server 2003,
Novell NetWare, IBM OS/2,
Mac OSX, AppleShare IP,
UNIX and
Linux.




Network advantages running a NOS is better than a stand a lot PC because it provides your users access to applications over a network. or the cloud. with the cloud, you can do many things, for example:
  • its lower cost. it saves you money by reducing the need to buy new hardware for software licensing.
  • File sharing, you can share endless about of data with your network using a database.
  • support, you don't have to upgrade all the computer in your organization. the upgrade only needs to be done on the server.
  • security, you manage all the computers on the network so you know where everything is at


Network Disadvantages
just because you have a network OS, doesn't mean there are pitfalls,
  • compatibility, not all software will be compatible with the hardware on the network computer.
  • disaster prevention, you have one single point of failure, which means that if the network OS goes down, the whole computers on the network go down.


Notes: some examples of NOS are: windows 2000, windows 2003, linux server, unix server like red hat, sun os