title: Difference between NSWindowController Vs NSViewController
body: <p>I am coming from <strong>iOS</strong> background and starting to learn Cocoa. On <strong>iOS</strong> unless we have multiple targets for <code>iPad</code> and <code>iPhone</code> we usually have <strong>one Window</strong> and manage the screen using <code>UIViewControllers</code>. Where every new screen will most of the time will map to a <code>UIViewController</code>. </p>
  
  <p>However on cocoa this seems to be the otherway around where  a new screen/window is manage by <code>NSWindow</code> and it's subcomponents are managed by <code>NSViewController</code>. So if I have multiple window app I should have separate <code>NSWindowController</code> for each window.  </p>
  
  <p>Is this approach correct or am  I having a misunderstanding ? </p>