title: React.js: The difference between findDOMNode and getDOMNode
body: <p>Could somebody tell me what's the difference between</p>
  
  <pre><code>React.findDOMNode(this.refs.email).value
  </code></pre>
  
  <p>and </p>
  
  <pre><code>this.refs.email.getDOMNode().value
  </code></pre>
  
  <p>They are doing the same thing - getting the value of element, but where should I use which one.</p>