Final answer:
A Unicast MAC address is a unique identifier assigned to a device on a LAN for one-to-one communication.
Step-by-step explanation:
A Unicast MAC address, integral to network communication, is assigned to a network interface card, serving as a distinct identifier for a device within a Local Area Network (LAN).
Unlike multicast or broadcast addresses, Unicast addresses are unique and specifically designate a singular destination device.
They facilitate precise one-to-one communication between devices on the network. The least significant bit of the first octet is crucial, set to 0 in a Unicast address, distinguishing it from multicast addresses where this bit is set to 1.
This binary distinction ensures that data packets with Unicast addresses reach the intended device, contributing to the efficiency and accuracy of network communication by preventing unnecessary broadcasting or multicasting.