What is a Network operating system (NOS)?

• A network operating system (NOS) is a computer operating system (OS) that is designed primarily to support workstations, personal computers and, in some instances, older terminals that are connected on a local area network (LAN). 
• The software behind a NOS allows multiple devices within a network to communicate and share resources with each other.
• The composition of hardware that typically uses a NOS includes a number of personal computers, a printer, a server and file server with a local network that connects them together. 
• The role of the NOS is to then provide basic network services and features that support multiple input requests simultaneously in a multi user environment.
• Due to earlier versions of basic operating systems not being designed for network use, network operating systems emerged as a solution for single-user computers.

Types of network operating systems

• There are two basic types of network operating systems.

1. The peer-to-peer NOS and 
2. The client/server NOS

The Peer-to-peer NOS

• Peer-to-peer network operating systems allow users to share network resources saved in a common, accessible network location. 
• In this architecture, all devices are treated equally in terms of functionality. Peer-to-peer usually works best for small to medium LANs and is cheaper to set up.

The client/server NOS

• Client/server network operating systems provide users with access to resources through a server. 
• In this architecture, all functions and applications are unified under one file server that can be used to execute individual client actions regardless of physical location. Client/server tends to be most expensive to implement and requires a large amount of technical maintenance. 
• An advantage to the client/server model is that the network is controlled centrally, makes changes or additions to technology easier to incorporate.

Common features of network operating systems

• Features of network operating systems are typically associated with user administration, system maintenance and resource management functionality. This includes:

• Basic support for operating systems like protocol and processor support, hardware detection and multiprocessing.
• Printer and application sharing.
• Common file system and database sharing.
• Network security capabilities such as user authentication and access control.
• Directory
• Backup and web services.
• Internetworking.
• Examples of network operating systems
• True network operating systems are categorized as software that enhances the functionality of operating systems by providing added network features. A few examples of these network operating systems and their service providers are: