title: iOS - pushViewController vs presentModalViewController difference
body: <p>What is the difference beetween calling <code>presentModalViewController</code> and <code>pushViewController</code>, when :</p>
  
  <ul>
  <li>animation is set to NO (even if yes, that's just an animation style that can be changed).</li>
  <li>a navigation controller is defined when presenting the modal view, so it can be navigable too, with a call stack, ....</li>
  </ul>
  
  <p>Is this just to be able to go back from the first pushed view ?  Woooaaaaaa.....   </p>
  
  <p>I guess the difference is elsewhere and deeper. No ?</p>