Advanced Placement (AP) Computer Science

What defines a public IP address?

1. An IP address used internally within a network

2. An IP address that is hidden from the public

3. An IP address logged by servers when connecting from the internet

4. An IP address associated only with secure websites

The correct answer is: An IP address logged by servers when connecting from the internet

A public IP address is defined as an address that is accessible over the internet and is used to uniquely identify a device on the global internet. It allows devices from different networks to communicate with each other. This contrasts with a private IP address, which is used within local networks and is not routable on the internet. Option C refers to the logging of an IP address by servers when a device connects from the internet. While it's true that servers often log the public IP addresses of incoming connections, this alone does not define what a public IP address is. Public IP addresses are assigned by an Internet Service Provider (ISP) and can be seen by anyone on the internet. They are essential for facilitating communication between devices across different networks, enabling web browsing, data transfer, and other internet services. Understanding that public IP addresses are vital for internet connectivity helps clarify their role in networking and reinforces their distinction from private IP addresses, which exist behind routers and are used for internal communication within a local area network (LAN).