How is a network interface card uniquely identified?

A network interface card (NIC) is uniquely identified by its Media Access Control (MAC) address, which is a hardware address assigned by the manufacturer. The MAC address is a 48-bit number, usually represented as six pairs of hexadecimal digits, and is embedded in the NIC's firmware. This unique identifier allows devices on a network to communicate with each other effectively and ensures that data packets are sent to the correct destination.