Design + Code an Android App from Scratch
This video discusses how an Activity works in Android and what are the methods that an Activity class provide and how and when the Android system calls these methods. It then illustrates the recent activities running on the phone and the Activity back stack which is basically the list of screens that the person is navigating through. The currently active screen is at the top of the stack and when you press the back button, it is removed from the top and destroyed bring the last Activity the user was engaging with to the top of the stack. Finally the video introduces the methods involved in the Activity lifecycle which you need to use as a developer in your apps to handle certain situations.