What is a MAC Address?
A MAC address is a unique identifier that’s associated to an individual network interface card (NIC). I like to think of them like a Social Security Number for a computer i.e. they are unique and only exist for that particular computer. MACs are what allows the Internet to work, for without them, there would be no Internet.
MAC addresses are also referred to as Hardware Addresses or Physical Addresses that uniquely identify network interface cards on a Local Area Network (LAN). MAC addresses are 12-digit hexadecimal numbers equaling 48 bits or 6 bytes in length. As illustrated in figure 1 below, the first 3 bytes are referred to as the Organizational Unique Identifier or (OUI). This essentially identifies the manufacturer or vender of the physical network card. The last set of 3 bytes represents the specific ID assigned by the manufacturer to that particular network adapter.