If you want to know what RAIL is without watching a video: <a href="https:&#x2F;&#x2F;developers.google.com&#x2F;web&#x2F;tools&#x2F;chrome-devtools&#x2F;profile&#x2F;evaluate-performance&#x2F;rail?hl=en" rel="nofollow">https:&#x2F;&#x2F;developers.google.com&#x2F;web&#x2F;tools&#x2F;chrome-devtools&#x2F;prof...</a>