This document defines and describes different types of computer networks. It begins by defining a computer network and its basic components like nodes. It then describes four main types of networks: local area networks (LANs), personal area networks (PANs), metropolitan area networks (MANs), and wide area networks (WANs). For each type, it provides examples and characteristics, such as LANs connecting computers in a building and WANs extending over large geographic areas like countries. It concludes by listing some advantages and disadvantages of computer networks and technologies that may influence their future, like AI, the cloud, and 5G.