Whether you work in a wired network office or a wireless one, one thing is common for both environments: It takes both network software and hardware (cables, routers, etc.) to transfer data from your computer to another—or from a computer thousands of miles away to yours.And in the end, to get the data you want right to YOU, it comes down to addresses.So not surprisingly, along with an IP address (which is networks software), there's also a hardware address. Typically it is tied to a key connection device in your computer called the network interface card, or NIC. The NIC is essentially a computer circuit card that makes it possible for your computer to connect to a network.An NIC turns data into an electrical signal that can be transmitted over the network

Media Access Control.. its burnt address. 48 bits hexa decimal number.. unique address. its place in NIC card.

MAC (Media access control)  is a pysical address of device,Unique and in hexadecimal form. It is 48 bit.

MAC is a machines Physical address, The internet is addressed based on a logical addressing approach. Say,when the packet reaches say the bridge connection a LAN, the question is..how does it identify, which computer it needs to send the packet to. For this it uses the concept of ARP, Address Resolution Protocol, which it uses over time to build up a table mapping from the Logical addresses to the Physical addresses. Each computer is identified using its MAC/Physical address ( u can use the ipconfig -all option to get ur MAC address).