NIC

NIC - "Network Interface Card"

Computer hardware that allows a computer to communicate over a computer network, commonly through wired or wireless connections. Nearly all modern motherboards have built-in or onboard NICs, but they also exist as either ISA or PCI expansion cards for desktops and PCMCIA cards for laptops, and there are also some external NICs that connect by USB. Most HP Printers use NICs called JetDirect cards.

Every NIC has a unique identification number called a MAC address (sometimes called the ethernet address or physical address) that is used in QIP to allocate an IP address to the machine the NIC is installed in.

More detailed information can be found here.