This document provides an overview of computer networks and networking concepts. It defines common network types including LANs, WANs, MANs, CANs, PANs, and SANs. It also describes common networking devices like servers, clients, hubs, switches, routers, and gateways. The document discusses widely-used networking standards and protocols including Ethernet, Token Ring, IP, TCP, UDP, IPv4, IPv6, and others. It provides a brief overview of technologies like ATM, SONET/SDH, and wireless networking.