What Protocol Provides connections to computers over a TCPIP network?

NIC (Network Interface Card) is a device that makes possible your computer to connect to the network

you must insert your NIC in PCI slot of a computer connect CAT 5 cable to the NIC

assign IP addresses to computers and in such a way let TCP/IP (networking protocol) do its job :)

http://embarq.centurylink.com/embarq/media/images/promo/residential/HSI_nic_display.gif