A MAC address (ALSO called an Ethernet address or an IEEE MAC address) is a number (typically written as TWELVE HEXADECIMAL digits, 0 through 9 and A through F, or as six hexadecimal numbers separated by periods or colons, i.e. 0080002012ef, 0:80:0:2:20:ef) which uniquely identifes a computer that has an Ethernet interface.
Unlike the IP number, it includes no indication of where your computer is located. In DHCP’s typical use, the server uses a requesting computer’s MAC address to uniquely identify it.

A MAC address (also called an Ethernet address or an IEEE MAC address) is a number (typically written as twelve hexadecimal digits, 0 through 9 and A through F, or as six hexadecimal numbers separated by periods or colons, i.e. 0080002012ef, 0:80:0:2:20:ef) which uniquely identifes a computer that has an Ethernet interface.
Unlike the IP number, it includes no indication of where your computer is located. In DHCP’s typical use, the server uses a requesting computer’s MAC address to uniquely identify it.