Commonly called a "NIC" (network interface card) or simply network card, is a printed circuit board that plugs into both the clients (personal computers or workstations) and servers and controls the exchange of data between them.

MAC is the protocol that controls access to the physical transmission medium on a LAN. MAC layer functionality is built into the network adapter and includes a unique serial number that identifies each card.

The MAC address can tell which vendor made the network adapter. The first three bytes of the six-byte field is called the OUI and is administered by the IEEE. E.g, 00-60-1D (hex) is used by Lucent Technologies and 00-01-43 (hex) is for Cisco Systems, Inc.

It means 16. The base 16 numbering system is used as a shorthand for representing binary numbers. Each half byte (four bits) is assigned a hex digit as shown in the following chart with its decimal and binary equivalents. Hex values are identified with an "h" or dollar sign, thus $3E0, 3E0h and 3E0H all stand for the hex humber 3E0.