A local area network (LAN) connects computers within a building or nearby buildings to allow users to share devices, programs, files and emails. Each computer connects to the LAN through a network card installed in the computer with an RJ45 port. Switches are networking devices that have multiple RJ45 ports and are faster than hubs, knowing which computers are connected to each port. Routers connect multiple networks, with home networks typically using a wireless router. The TCP/IP protocol ensures reliable transfer of information between different operating systems and networks by using TCP to reliably transfer data and IP to deliver it to the destination computer identified by its unique IP address.