What is referred to as the hardware address of a device on a network?

The correct answer is the MAC address, which refers to the hardware address of a device on a network. The MAC address is a unique identifier assigned to network interfaces for communications at the data link layer of a network. This 48-bit address is typically expressed in hexadecimal format and is used to ensure that data packets are directed to the correct hardware device within a local network.

In contrast, an IP address serves a different purpose. It identifies a device on a network at the network layer, providing a way to route packets between different networks. While both the IP address and MAC address are essential for network communication, the MAC address specifically designates the hardware of the device, differentiating it from logical addressing schemes like the IP address.

A host address is more of a general term and can refer to both IP and hostname representations of addressing on a network, which does not specifically denote the hardware aspect. Similarly, a subnet address relates to dividing a network into smaller, manageable sub-networks but does not pertain to the physical hardware identification of a device. Thus, the MAC address is the definitive term used for the hardware address of a device on a network.