With a Video page, you can add videos from YouTube or Vimeo to your app. They'll play right within the pages. Just click the "+" sign in the upper right corner, then insert the video's URL.
NOTE: You cannot add private videos, channels or users to the Videos page, only Videos by direct link. Get all the settings specifications for adding videos.
If you want to delete a video, just click the 'x' next to the name in the right well. To rearrange it, drag and drop from that same column.