Devices that connect to a network have a unique identifier known as a _____ address.

A device that connects to a network is assigned a unique identifier known as a MAC address. A Media Access Control (MAC) address is a hardware address that identifies each device on a network uniquely. It usually consists of six pairs of hexadecimal digits and is embedded in the network interface controller (NIC) of the device. This unique identifier plays a crucial role in local area networks (LANs), allowing devices to communicate with each other.

While IP addresses are also identifiers used for devices on a network, they are not unique in the same way that a MAC address is. IP addresses can change when devices connect to different networks or in cases of DHCP (Dynamic Host Configuration Protocol) assignments, whereas the MAC address remains constant for the device’s manufacturing lifetime.

HTTP and TCP are protocols related to data communication over networks but do not serve as unique identifiers for devices. HTTP (Hypertext Transfer Protocol) is used for transmitting hypermedia documents, while TCP (Transmission Control Protocol) is a core protocol of the Internet Protocol Suite that ensures the delivery of data packets. Therefore, in the context of identifying devices on a network, the MAC address is the correct terminology.