onCreate
: Activity launched for the first time. Here is where you may initialize your stuff.onResume
: User returns to the activity after another activity comes into foreground. (onPause
)onRestart
: User navigates to the activity after it's no longer visible (onStop
).
You can see the complete lifecycle on Activity documentation. Your activity stuff would only be lost when onDestroy
is called, which happens when you finish it, or when it's destroyed by the system (i.e. when apps with higher priority need memory)