title: What is the difference between this, self, window and window.self
body: <p>If I open an empty page and I run the following command in javascript console I obtain the same result:</p>
  
  <pre><code>  &gt;&gt;&gt; this
    DOMWindow
  
    &gt;&gt;&gt; self
    DOMWindow
  
    &gt;&gt;&gt; window
    DOMWindow
  
    &gt;&gt;&gt; window.self
    DOMWindow
  </code></pre>
  
  <p>What do they refer to? ...the same object or what else?</p>