Wide area network

A computer network that spans a relatively large geographical area.

Server Operating System

The same as the internet.

Server

 Computer or Sotware that performs administration or coordination functions within a Network.

Router

 A device that allows packets of data to be moved efficiently between two points on a network.

Public Switched Telephone Network (PSTN)

 The collection of interconnected systems operated by the various telephone companies and administrations.

Proxy server

 A computer that acts as an intermediary between a client machine and a server.

Peer-Peer network

A network of personal computers.