Explain the concept of port forwarding.

Port forwarding is a network configuration technique that enables external devices to access services on a private network. Specifically, it works by directing incoming traffic from one IP address and port combination to another internal IP address and port combination on a local network. This is particularly useful in situations where you want to allow external users to connect to a specific service hosted on a device within your network, such as a web server, game server, or camera.

For instance, when you configure port forwarding on a router, you're telling it to send packets arriving at a specified port (like port 80 for HTTP) to a specific device on your local network (for example, a computer with an internal IP address of 192.168.1.10). This means that users on the internet can access the service running on your local device by pointing their requests to your public IP address and the designated port. This capability makes it essential for hosting services while ensuring that the local network remains secure and organized.

Other choices reflect different networking concepts that do not align with the specific function of port forwarding. For instance, redirecting internal traffic does not imply external accessibility, blocking access pertains to security measures that prevent connections, and monitoring port activity is about tracking usage rather than enabling communication.