Port Forwarding (or port mapping) allows external traffic from the internet to connect to a device, like a computer, on a private network.
Say you want to host a Minecraft server for your friends on your computer. When they try to connect, their traffic has to be sent to the correct computer on your network, and their connection must be permitted by your router. Your router uses port forwarding rules to sort out which computer should be sent the traffic relating to the Minecraft server. Of course, it isn’t just game servers — if it involves internet traffic, ports are involved.
See
How to Port Forward on Your Router#
technology #
portforwarding #
networking 
Although modern Wi-Fi routers handle most functions automatically, some applications will require you to manually forward a port in your router’s settings. Fortunately, it’s very simple to forward ports on a router if you know where to look
