A media access control address (MAC address), also called physical address, is a unique identifier assigned to network interfaces for communications on the physical network segment
How can I find my device’s MAC Address?
There are many different ways to find the MAC address of your device and it depends on what kind of device it may be. One of the easiest ways if you still have the physical packaging that came with the device is to look on the box for a code that is 12 characters long and a mix of letters and numbers separated by colons or dashes.
To find the MAC address of a interface on a windows computer you can see Tom’s hardware guide here: http://www.tomsguide.com/faq/id-2379887/find-laptop-mac-address.html
If it is a phone or TV or other device the easiest way to find out how to find your MAC address would be to google search.
For example “How to find MAC Address AppleTV”