Learning how to use software like Microsoft Excel, or gaming engines like Playcanvas or Unreal Engine 4, will involve you doing some practicing on those actual platforms. For those courses we have videos you can follow along to for the exercises. Check out the video below showing you a neat trick to help you watch the videos without bouncing between browser and the platform.
Note that it doesn’t matter which browser you are using. Google and Vimeo have this feature embedded on every video. So whether you are using Safari (for Macs) or Mozilla Firefox or the pitiful Internet Explorer, Picture in Picture will work the same as illustrated in the video above.