A Media Access Control (MAC) address is a unique identifier assigned to network interfaces for communications on a physical network. It is used to ensure that data packets are sent to the correct device within a local area network (LAN). Each MAC address is typically represented as a series of six pairs of hexadecimal digits, separated by colons or hyphens. MAC addresses operate at the data link layer of the OSI model, allowing devices like computers, routers, and smartphones to identify and communicate with each other. Unlike IP addresses, which can change based on the network, a MAC address is usually fixed and tied to the hardware of the device.