Networks are everywhere today, from Bluetooth personal area networks, to Local Area Networks in the home and office, to Wide Area Networks connecting remote offices, the cellular networks carrying mobile voice and data, and the big one which combines all networks, the internet. Network infrastructure describes the many components enabling networks. This includes hardware like modems, hubs, switches, routers, gateways, repeaters and more, and software services such as monitoring and management tools, operating systems on the hardware devices. Network Infrastructure even includes media contained on and transmitted through the network.