title: What does Array.prototype.slice.call() & wrapper.querySelectorAll() do?
body: <p>I found following cone in a js plugin</p>
  
  <pre><code>var container = document.getElementById( 'vs-container' ),
  wrapper = container.querySelector( 'div.vs-wrapper' ),
  sections = Array.prototype.slice.call( wrapper.querySelectorAll( 'section' ) ),
  links = Array.prototype.slice.call( container.querySelectorAll( 'header.vs-header &gt; ul.vs-nav &gt; li' ) );
  </code></pre>
  
  <p>I couldn't understand what does <code>Array.prototype.slice.call()</code> &amp; <code>wrapper.querySelectorAll( 'section' )</code> do in above code. I've not seen them before so I would like to know what they actually do.</p>