Activity Life Cycle in Android.

There are 7 stages in Activity Life Cycle. Activity Manager  manages these activities.
It shows your activity are on which state.

7 methods are :

1- onCreate()
2- onStart()
3- onResume()
4- onPause()
5- onStop()
6- onDestroy()
7- onRestart()

Your Activity can be destroy from onStop() or onRestart().

Created: In this method activity should create its UI.

Started: In this state activity is about to start,it is completely invisible.

Resumed: In this state Activity's UI is completely visible on screen.

Paused: Activity is about to unload or cover because of another activity,in this state activity is completely visible on scree.

Stopped: Activity is unloaded or another activity has fully covered the first activity,in this state activity is
completely visible.

Destroyed: In this state activity is already unloaded and about to get destroyed.

Restarted: In this state activity is about to restart because of uncovering.