How do push notifications work?

Question

Push technologies

Hello. Tell me how push mailing works. Where to begin?

Answer 1

Push notifications are TCP / IP packets that the server sends to clients connected to it and keeping the connection open (keep-alive), start ideally from two sides at once, on the one hand, the implementation of the simplest client-server (TCP / IP) application, and on the other hand, studying ready-made libraries for push notifications, such as Google cloud messaging.