title: ansible vars_files vs include_vars
body: <p>What is the difference between</p>
  <ul>
  <li><p><code>vars_files</code> directive</p>
  <p><strong>and</strong></p>
  </li>
  <li><p><code>include_vars</code> module</p>
  </li>
  </ul>
  <p>Which should be used when, is any of above deprecated, discouraged?</p>