You'll find information on what ports are required to be accessible to play certain games, get a service in an application to work or run servers in abundance on the Internet. For example, EA Games ...

Port forwarding is a crucial networking technique that allows you to make a computer or device on your local network accessible to the internet, bypassing the security features of your router. This is ...

A mesh VPN with controlled, deliberate access control is far more secure than port forwarding ...

The top picture is of a wondrously cheap router which uses a very common web admin interface. It lets you specify a range of incoming ports, but only one port to forward to. I'd imagine the latter is ...