What is the purpose of a MAC address?

A MAC (Media Access Control) address is a unique identifier assigned to network interfaces for communications on the physical network segment. The primary purpose of a MAC address is to uniquely identify a device on a local area network (LAN). Each device that connects to a network, such as computers, printers, and routers, has a unique MAC address, allowing devices to identify and communicate with each other.

This uniqueness is essential for the functioning of networking protocols, as it ensures that data packets are delivered to the correct device. Unlike IP addresses, which can change depending on the network, MAC addresses remain constant for the hardware. This consistency helps in network management and device identification.

Depending on the context of the question, other options do not align with the role of a MAC address. For example, MAC addresses do not serve to identify URLs, motherboards, or email clients, as they are specifically designed for device identification at the data link layer within a network.