As Android developers we inevitably have to learn about the activity lifecycle and how it works. Its important that we know which states our activities go through when a user navigates through our app, out of it or back into it, so we can do the right operations at the right time and avoid crashes and other bugs.
For this reason we want to take a closer look at the activity lifecycle in this video and especially at its 7 main callbacks: onCreate, onStart, onResume, onPause, onStop, onDestroy and onRestart.