This document discusses computer networks and provides details about three main types: LAN, MAN, and WAN. It defines each type of network and provides examples. LAN connects computers in a small local area like a home or office using cables or wireless connections. MAN connects LANs across a larger metropolitan area, using fiber optics and routers. WAN spans the largest areas like countries and continents, with the Internet as a common example, connecting LANs globally through Internet service providers.