A MAC address (Media Access Control address) is a unique identifier assigned to network interfaces for communication at the data link layer of a network segment. MAC addresses are used by network devices to identify themselves on a network and to communicate with each other.
MAC addresses are typically written as a 12-digit hexadecimal number, such as 00:11:22:33:44:55. The first six digits of a MAC address identify the manufacturer of the network interface, and the remaining six digits are assigned by the manufacturer to uniquely identify the device.