The physical device, or hardware, address is also referred to as the media access control (mac) address. Amac address is a unique number that is assigned to a network interface card (nic) card when the card is manufactured. No two computers on a network can have the same mac address. The data link layer of the OSI model uses these addresses to communicate between devices on local network segments. Although these addresses are considered permanently assigned, some protocols enable them to be changed. An example of a MAC address is 00-aa-00-62-a1-09.
