Wait, doesnt the firewall protect your connection from harm?
At least, its done for a while, just to allow them to allow the access.
This is the main function of the app, so you might do everything easily and effortlessly.

It means that your firewall is still activated, while giving you the required access altogether.
The app provides direct access (from outside) to private networks.
Without it, the external devices wont be able to see the internal parts of the IP addresses.

A port itself refers to a communication endpoint.
Its typically known as a (port) number associated with IP address.
Dont get me wrong; this kind of app is only handy when you do allow such a thing.

Why should you use this app, anyway?