You can embed videos into your posts or pages from a video hosting platform such as YouYube or Vimeo.
VIMEO
Go to the Vimeo video you wish to add and click SHARE (over the top right of the video) – copy the EMBED link (or customize this first by clicking SHOW OPTIONS and changing the colours, size etc)
YOU TUBE
Go to the YouTube video you wish to add and click SHARE (just below the video) – copy the EMBED link (or customize this first)
Make sure you are in the TEXT mode then paste the copied code into the page where you wish the video to be.
PUBLISH or UPDATE