android why sending information to server works with WIFI only?

Question

I am sending information to a server via WIFI and everything works great.Now i want to send information to a server with mobile data too, and i do not know why only works with W

Answer 1

You cannot contact your server from the device's mobile network unless it is routable from the public Internet.

A server running on your development machine or otherwise behind a NAT/firewall would typically only be accessible from your local network / wifi.