title: DMIDecode product_uuid and product_serial.what is the difference?
body: <p>There are <code>product_uuid</code> and <code>product_serial</code> files in dir <code>/sys/class/dmi/id/</code>.</p>
  
  <ol>
  <li>How it are generated? What is the difference? </li>
  <li>Can I change this files? </li>
  <li>Is it save a value after reinstall operation system?</li>
  </ol>