The permanent hardware address engraved on a network interface card at manufacture is the:

1. Every node on a network needs a unique identifier so data can be routed to it. 2. The MAC address, also called the physical or hardware address, belongs to the NIC. 3. It is engraved on the NIC at the time of manufacturing, so it is permanent and cannot be changed. 4. An IP address, by contrast, can change when a node moves to a different network. 5. A domain name is a readable label for a server's IP address, not a hardware identifier. _Source: syllabus Computer Science Class 12, Ch 10 'Computer Networks', S10.6.1 MAC Address_