title: What is the point of double install in gulp?
body: <p>The getting started for gulp is:</p>
  
  <pre><code>npm install --global gulp
  npm install --save-dev gulp
  </code></pre>
  
  <p>I understand the first install is to install the binary in global path, but ..</p>
  
  <ul>
  <li>what is the point of the 2nd install? </li>
  <li>can't it be also global?</li>
  </ul>