Assuming that we made port forwarding all out outdoor connection to our Raspberry Pi Zero W, we can easily connect to it from anywhere in the world by simply using the external IP of our home. For example, if you google find my ip and come up with a result like 45.12.64.23, then all you need to do is close the Wi-Fi connection from your mobile phone and using the data try to go to http://45.12.64.23/ (obviously change that to your IP address). You should be able to communicate with your Raspberry Pi like that at port 80. HTTP port is the number 80 and this is the port that you are requesting when you type in a URL such as http://XXX. You can specify your port in the URL by typing http://45.12.64.23:<port> and as a result you are connecting your device with your home in port <port>, where port is a number from 1000 to 4000. Actually, there are more ports but if you are not an advance user, stay at this range.