This isn't too technical of a question.
I'm currently writing an article for push notifications on Android devices. I don't need code, per se, but if a user is logged out of an application (via the system timing out), how do they receive push notifications? My goal for this article is to verify users are still getting push notifications for an application or product even if they're logged out. Unless, of course, the user dictates otherwise.
Is it tokens to verify user authentication + subscription? A class library?