title: what does "frames with intermittent jank" means in Chrome DevTools docs?
body: <p>I got confused when I read <a href="https://developer.chrome.com/devtools/docs/tips-and-tricks#counter-display" rel="nofollow">Chrome DevTools |Timeline</a>.</p>
  
  <blockquote>
    <p>Keep in mind that just tracking the FPS counter may lead to you not noticing frames with intermittent jank. Be careful when using the content. It is also worth noting that FPS on desktop does not equal FPS on devices and special care should be taken to profile the performance there too.</p>
  </blockquote>
  
  <p>does <code>frames with intermittent jank</code> means the frame that fail to use real hardware frame?</p>