A Media Access Control (MAC) address is a unique identifier assigned to a network interface controller (NIC) for use in communications within a network segment. It functions as a physical address, distinguishing a specific device from others on the same network. For example, every smartphone, including those running the Android operating system, possesses such an identifier associated with its Wi-Fi and Bluetooth interfaces. It’s typically represented as a 12-character hexadecimal number, such as `00:1A:2B:3C:4D:5E`.
This identifier plays a crucial role in network administration, security protocols, and device tracking. Network administrators often use it to filter network access, allowing only authorized devices to connect. It is also a component in security measures like MAC address filtering, which prevents unauthorized devices from joining a network. Historically, it has been used in location services and targeted advertising, though such uses are subject to privacy considerations and regulations.