What is MAC Address?

MAC, Media Access Control, address is a globally unique identifier assigned to network devices, and therefore it is often referred to as hardware or physical address. MAC addresses are 6-byte (48-bits) in length, and are written in MM:MM:MM:SS:SS:SS format. The first 3-bytes are ID number of the manufacturer, which is assigned by an Internet standards body. The second 3-bytes are serial number assigned by the manufacturer.
 
MAC layer represents layer 2 of the TCP/IP (adopted from OSI Reference Model), where IP represents layer 3. MAC address can be thought of as supporting hardware implementation whereas IP address supports software implementation. MAC addresses are permanently burned into hardware by hardware manufacturer, but IP addresses are assigned to the network devices by a network adminstrator. DHCP relies on MAC address to assign IP addresses to network devices.

How do I find a MAC address of network device

Operating Systems support various command-line and GUI utilities to allow users to find MAC address of the system.

On Unix variants including Solaris and Linux support “ifconfig -a”, “ip link list” or “ip address show” command that displays MAC address of the network.

On Windows type :

ipconfig/all

now look for physical address of the card you are targeting.

The above image shows you the mac address of the lan card, If you are finding mac address for wireless card please look for the group of wireless devices and look for physical address of that device.