Network interface cards (NIC)

A Network interface card enables a computer system to communicate with the other computers/networks using unique MAC(Media Access Control) addresses encoded on each card’s chip, the NIC formats, sends, receives data and controls the data flow between the computer and the network when transmitting information the NIC transfers frames of data to the  physical layer which in turn will transmit the data to the physical link, for the receiver the Network Interface card processes the bits received from the physical layer and will process the message based on its contents, you can have either wired(using cables and connectors) or wireless network(using an antenna that works with radio wave technology) interface cards, most modern NIC are wireless but also have wired support.