What is the unique identifier for network hardware called?

What is the unique identifier for network hardware called?

• Gettysburg address
• MAC address
• IP address
• Network address 

 

EXPLANATION

A media access control (MAC) address is a unique identifier associated with network hardware for communicating on the physical network.
A media access control address of a device is a unique identifier assigned to a network interface controller for communications at the data link layer of a network segment. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet and Wi-Fi. In this context, MAC addresses are used in the medium access control protocol sublayer.