How to properly check backend for updates in background?

Question

Android

Good day to all
There will be 2 related questions in this question :)

1. How to check for updates on the back if the application has not even been launched yet? Like how gmail does it by checking for new emails; telegram, vk for messages

2. If the application has already been launched, then you can, for example, register the AlarmManager so that it launches the IntentService every n seconds, where it, in turn, would make a request for backing and, if something new appeared - launched push-notification with some information and died. But this approach is possible only if the application has already been launched. Is this method acceptable for this task?

I apologize in advance if I'm asking something obvious and simple.

Answer 1

This is done through push notifications .