title: I don't fully understand sendSubviewToBack. Please, see the code
body: <p>You can see my screenshot of xib's file.</p>
  
  <p><img src="https://i.stack.imgur.com/PsSiG.png" alt="enter image description here"></p>
  
  <p>I do some manipulation in viewDidLoad</p>
  
  <pre><code>-(void) viewDidLoad
  {
   [smallView removeFromSuperview];
   [bigView sendSubviewToBack:smallView];
  }
  </code></pre>
  
  <p>Will the hierarchy change from view->bigView->smallView to view->smallView->bigView?</p>