何时使用getSharedPreferences vs savedInstanceState？

I'm trying to figure out when to use a saved instance state versus loading information from a shared preferences file. I have two variables that I wish to save, time and score. I want to make sure that if the user returns to the game screen that their score and time is saved and restored regardless if it's from onPause state or onStop. I'm trying to figure out when to use a saved in