By default, video controls are hidden from the user. Video controls include play, pause, volume, closed captions, and other settings found at the bottom of a video.
Enabling “Video Controls Display” will show all of these controls to the user, and allow them to have more control over the video.
If you use videoes from Vimeo, the Video Controls Display setting will not affect the videoes. In order to edit control settings, go to your Vimeo account (see picture below).