The MAC address is a unique value associated with a network adepter. MAC addresses are also known as hardware address or physical address. They uniquely identify an adepter on a LAN. MAC addresses are 12 digit hexane decimal numbers. MAC addresses are usually written in one of the following two formats is MM:MM:MM:SS:SS:SS.
MAC address is a unique hardware number assigned to network hardware such as NIC and router.
Why MAC addresses
TCP/IP and other main stream networking architecture generally adopt the OSI model. MAC addresses function at the data link layer and allow computers to uniquely identify themselves on a network at this relatively low level.
MAC vs. IP address
MAC addressing works at the data link layer whereas IP addressing functions at the network layer.
The MAC address generally remains fixed and following network device but IP address change as the network device moves from one network to another.
IP network maintain a mapping between IP address of a device and its MAC address.
DHCP (Dynamic Host Configuration Protocol) also usually relies on MAC addresses to manage the unique assignment of IP address to devices.