title: What does INSTALLED_APPS setting in Django actually do?
body: <p>What does this <em>actually</em> do? I recently branched out my project from 1 app into 6 different apps and forgot to update the <code>INSTALLED_APPS</code> part of my settings file. Everything still works even though I didn't list the new apps in. Is that supposed to happen? Do I need to include all my apps in <code>INSTALLED_APPS</code>? </p>