Network service is an application that is used to manage complex network for smooth functioning. Running at the network application layer, a network service offers file storage, presentation, modification, communication, and so on depending on the network protocols. Additionally, network service include: management security devices such as firewalls, IPS devices (Intrusion Prevention Systems), and VPN (Virtual Private Network) access devices.
Technically, a network service is offered by a server component that runs on single or multiple computers. The service can be accessed via a network by client systems. Both client components and server components can be run on one machine, usually having a user-interface.
TCP-IP based Network Services works on a standard port number set by the Internet technical governance, such as email relay works on port number 25, and World Wide Web servers operate on a standard port number 80.
Directory services, Instant messaging, Video on demand, World Wide Web, Simple Network Management Protocol, Online game, Voice over IP, Printing, Time service, File sharing, Wireless sensor network, File server, and e-Mail are the other type of network services.