title: Difference between moment.toString() and moment.toISOString()
body: <p>I have reading <code>moment.js</code> document, there have  a <code>moment.toISOString()</code> function for helps to formats a string to the <em><code>ISO8601</code></em> standard. </p>
  
  <p><strong><code>Also there have a another one reason for why we use moment.toISOString()</code></strong></p>
  
  <blockquote>
    <p><code>moment.toISOString()</code> function using for performance reasons.</p>
  </blockquote>
  
  <p>I don't know <code>toISOString()</code> the performance best than <code>moment.toString()</code>.But only the result was difference while using <code>moment.toString()</code> and <code>moment.toISOString()</code>. </p>
  
  <hr>
  
  <h2>So my question is.</h2>
  
  <ul>
  <li><p>Why we should use  <code>moment.toISOString()</code>? for <strong><em>performance</em></strong> reasons? </p></li>
  <li><p>And what is the difference between <code>moment.toISOString()</code> and <code>moment.toString()</code>?</p></li>
  </ul>