Which term defines a unique identifier for network interfaces used in a local area network?

The term that defines a unique identifier for network interfaces used in a local area network is the MAC address. A MAC (Media Access Control) address is a hardware identification number that is assigned to a network interface controller (NIC) for communications at the data link layer of a network segment. This address is unique to each device and is hard-coded into the hardware, allowing it to be used for identifying devices on a local network.

MAC addresses are structured as six pairs of hexadecimal digits, typically displayed as "00:1A:2B:3C:4D:5E." This unique identifier plays a crucial role in the functioning of local area networks, as it enables devices to send and receive data to and from the correct destination. In contrast, an IP address is more suited for routing information over the internet rather than uniquely identifying hardware within a LAN. Similarly, a host name is a human-readable label assigned to a device that maps to its IP address, while a network ID refers to the identifier for a specific subnet within a network, not necessarily tied to individual devices.