What is the difference between a public and private IP address?

The distinction between public and private IP addresses centers on their intended use and the scope of their routability. Public IP addresses are designed to be accessible over the internet. They are unique across the entire internet and can be routed globally, allowing devices to communicate with one another over vast distances. This is critical for hosting websites, accessing online services, and facilitating communication between different networks.

In contrast, private IP addresses are meant for use within local networks, such as home or corporate intranets. They are not routable on the internet, meaning that devices with private IP addresses cannot directly communicate with devices that have public IP addresses. Instead, private IP addresses serve to organize and enable communication among devices within the same local area, helping conserve the limited number of available public IP addresses.

This significant distinction is why the first choice accurately captures the essence of the difference between the two types of IP addresses. The other options misrepresent the nature and purpose of public and private addresses, focusing on characteristics that are not inherently tied to their definitions and where they are used.