How to receive push notifications from the server in android?

Question

Android

The task is to receive push notifications from the server. What are the options to implement this?
How does it work, for example, in the VK application for android?
I am considering a websocket in the service, how practical is it and how will it affect battery consumption?

Answer 1

https://developers.google.com/cloud-messaging/

Answer 2

If you only need pushes. Maybe you don't need to do an application? Use for example the PushAll platform. Notifications for both android and computer just from the server via api. And you don't need to develop anything.