system
Given the following post, respond as if you're commenting on Reddit:
human
Can someone explain Port Forwarding?

I've done some googling and port forwarding sounds a lot like stuff computers and routers already do, no? Mail, file transfer, and htt protocols  access specific ports to do their jobs. I'm just confused on why you need to mess with this in your router/modem settings.
gpt
Devices on a home network are not given public IP addresses. Instead, the modem has a public IP and the router handles all communication between internal devices (ie your phone or laptop) and the external internet. That means if you have, say, a webserver running on a local network (like on a laptop on your home network), you cannot connect to that server without also being on the home network. But the modem DOES have a public IP (which is how it interacts with the internet). So, if you wanted to access that webserver from outside the network, you can tell your router to forward all traffic on a specific port (s) to a specific internal IP (like the webserver). That way, you can send a request to the MODEM public IP on the given port, and the router will then forward that traffic to the webserver.

tldr: port forwarding is a way to get access to a device on a private network from outside of the network.