title: Difference between $('selector')[0] ,$('selector').eq(index) in jquery.
body: <p>What is the difference between <code>$('#div1 a')[0]</code> and <code>$('#div1 a').eq(0)</code> for the following markup</p>
  
  <pre><code>&lt;div id="div1"&gt;
  &lt;a href="#"&gt;click&lt;/a&gt;
  &lt;/div&gt;.
  </code></pre>
  
  <p>Please Help.</p>