title: What's the difference between override_settings and modify_settings in Django?
body: <p>Django's <a href="https://docs.djangoproject.com/en/1.10/topics/testing/tools/#overriding-settings" rel="noreferrer">docs on testing tools</a> mention both the @override_settings and the @modify_settings decorators for usage in tests, but it is unclear from the docs (at least to me) what is the difference between them.</p>
  
  <p>So, what is it?</p>