title: What's the difference between Xcode's move to trash and remove reference?
body: <p>When I want to delete file in Xcode. Between "move to trash" and "remove reference" which one should I choose?</p>
  
  <p>I always choose <strong>move to trash</strong> before cause I thought it will definitely delete the real file. But not sure if that's right. So what is the difference between them?</p>