Your app almost certainly won't be the only app running on the user's mobile device. As such, the app needs to properly handle being backgrounded and then later being resumed by the operating system. The app should also have a strategy in place to deal with unexpected terminations as the operating system (or the user) might terminate any app at will.
pause event is fired when the app is being placed in the background by the user or by the operating system. The
resume event is fired when the user or the operating system brings the app back to the foreground. Note that there is no guarantee that your app will receive a
resume event after a
pause event; the operating system might terminate the app instead. ...