What does an IP address uniquely identify?

An IP address uniquely identifies every device on the Internet. This identification allows devices to communicate with each other over the network by providing a specific address that is essential for routing data to the correct destination. Each device connected to the Internet, whether it is a computer, smartphone, server, or any other kind of networked hardware, is assigned an IP address that distinguishes it from all other devices.

This is critical for the functioning of the Internet, as it ensures that data sent from one device can reach the intended recipient without confusion. The structure of the IP address and the method in which IP addresses are assigned—whether dynamically or statically—further establish this uniqueness across the vast network.

In contrast, while every user may utilize a device with a unique IP address, a single IP address can be shared among multiple users through technologies like NAT (Network Address Translation). Similarly, not every server in a data center or application on a device has its own public IP address; they may operate under a single IP address through shared resources or ports. This specificity about devices versus users, servers, or applications highlights why the correct answer centers on devices as distinct entities on the Internet.