The book begins with a brief history of the development of networks, including their origins and where they are heading. It describes network models such as centralized and decentralized, and distinguishes between a local area network (LAN) and a wide area network (WAN). The discussions include cable connections and termination for the Network+ exam; the meaning of convergence; and the most common network devices being used on small and large networks, including the Internet. The role of switches in improving network functionality and enhancing security is described. The book also contains chapters on wireless networking; Open Systems Interconnection (OSI) model; Transmission Control Protocol/Internet Protocol (TCP/IP); wide area network (WAN) technologies; network security; and network management and troubleshooting.