How do public IP addresses differ from private IP addresses?

Public IP addresses are assigned to devices that need to be accessible from the internet, allowing them to communicate with other devices and servers on a global scale. This accessibility is crucial for a range of online services and web applications, enabling users and devices worldwide to reach each other without restrictions. In contrast, private IP addresses are designated for use within a local network. They are not routable on the internet and serve to facilitate communication between devices within the confines of that local network, such as in homes or organizations.

This fundamental difference in accessibility is critical for understanding how networks are structured. Public IP addresses must be unique across the internet and require registration with a central authority to avoid address conflicts. Private IP addresses can be reused across different networks without such requirements, as they are only relevant within their specific local environments.

Understanding this distinction helps clarify why public and private IP addresses have different functions and requirements in networking.