title: What is the purpose of VOLUME in Dockerfile
body: <p>I'm trying to go deeper in my understanding of Docker's volume, and I'm having an hard time to figure out the differences / use-case of:  </p>
  
  <ul>
  <li>The <code>docker volume create</code> command</li>
  <li>The <code>docker run -v /path:/host_path</code></li>
  <li>The <code>VOLUME</code> entry in the <code>Dockerfile</code> file</li>
  </ul>
  
  <p>I particularly don't understand what happens if you combine the <code>VOLUME</code> entry with the <code>-v</code> flag.</p>