Mac addresses are physical addresses at layer 2 of the OSI model .
How does it work !
Hosts on a network will listen for packets that have their MAC address in the destination field of the packet . The Physical Layer understands the electrical signals on the network and creates the frame which gets passed to the Data link layer. If the packet is destined for the host then the MAC address in the destination field of the packet will match, so it will accept it and pass it onto the Layer 3 which, in turn, will check the network address of the packet (IP Address), to make sure it matches with the network address to which the host has been configured..
Mac addresses are in HEX , 48 bits or 6 bytes .
Reminder ( 1bytes = 8 bits )
The 1st 3 bytes or 24 bits or the Vendor Code set by the RFC – 1700
The other Half is for the Vendor to set serial numbers.
00-FF-01 is the Vendor Code and FA-C2-CF is the Vendor serials numbers.
Now lets convert this mac address into binary :