Android Lifecycle Overview
As I ventured into the Android world as a Developer, one of the first things I had to understand was the lifecycle of an Android App.
It is a big paradigm shift from traditional Java programming. Typically a Java app has a single entry point and everything happens there after in a kind-of sequential manner. An Android App can have multiple entry points, and it can be interrupted by any reason, like a phone call suddenly coming in, a memory manager killing your app when it goes to the background or just because the user wants to open another app from a notification.