In a local area network (LAN) or other network, the MAC (Media Access Control) address is your computer's unique hardware number. (On an Ethernet LAN, it's the same as your Ethernet address.)
A Media Access Control (MAC) address is a 64 or 48 bit addressing System linked to the hardware of network adapters.sometimes MAC address is also known as hardware address, or (BIA) burned-in address, or also called physical address. MAC addresses are expressed in hexadecimal form like 2AA:FF:FE3F:2A1C, and in the case of a 48-bit address, or 01-23-45-67-89-AB-CD-EF.
When you are connected to the Internet from your computer (or host as the Internet protocol thinks of it), a correspondence table relates your IP address to your computer's physical (MAC) address on the LAN is created.
The MAC address is used by the Media Access Control sub layer of the Data-Link Layer (DLC) of telecommunication protocols. There is a different MAC sub layer for each physical device type. The other sub layer level in the DLC layer is the Logical Link Control sub layer.