How to make Backend for Android?

Question

Android

There is a client application that must log in and send data, and at the other end there is an application for the dispatcher that reads this data. I heard that for this you need to create a server, Backend, Frontend. Help with information on how to create this server: what to read, what to watch? There is an understanding of the Java language.

Answer 1

If there is already an application on the other end, then what is the question then? You don't need a frontend - frontend is your android application.