The Network Interface Card Ethernet NICs have a RJ-45 port. Wave NICs have a transmitter/receiver connected to an antenna. All NICs have one thing in common, a media access control (MAC) address embedded in their hardware. This is a unique 48 bit code used to identify one NIC from another and is incorporated into every data packet sent from or received by a NIC. It is represented by 12 hexadecimal digits in sets of two, such as A1 B8 D4 30 95 27 74 13 4F 0E 23 48. The MAC address is used to move data between devices within a network.