A media access control address (MAC address) is a unique identifier for an Ethernet or network adapter over a network. It distinguishes different network interfaces and is used for a number of network technologies, particularly most IEEE 802 networks, including Ethernet. In the OSI model, MAC addresses occur in the Media Access Control Protocol sub-layer.
A MAC address is also known as physical address, hardware address and burned-in address.
MAC addresses are generally assigned by the vendor/manufacturer of every network interface card (NIC) developed. They are implemented in most network types, but unlike IP address, MAC addresses are permanent and can’t be changed. A MAC address is created using the specifications provided by IEEE.
Each MAC address consists of a 12-digit hexadecimal notation, which is embedded within the NIC firmware and is composed of a six-digit manufacturer’s organization unique identifier followed by a six-digit serialized or random unique identifier.
Hardware Address, Burned-In Address, Machine Address