Show a video on any of your pages. The video stays on its own site, such as YouTube or Vimeo, and your page plays it from there.
Before you start: upload your video to a video site, and get the video's embed code from that site. On YouTube, select Share under the video, then Embed, then copy the code in the box. Other sites have a similar embed or share option, and their help pages explain it. Copy the whole code.
In your admin, open the page, such as Bio in the Pages menu, and click in the text box where the video should go.

The Bio page with the content editor open Select the Embed Code button, the filmstrip icon in the editor's second row. The Embed Dialog opens.

The Embed Dialog with an empty box under Paste Embed Code Here Click in the box and paste the code with Ctrl+V on a PC or Command+V on a Mac.

The Embed Dialog with a video's embed code pasted in Select OK. The editor may show only blank space where the video will be, so do not worry if you cannot see it.

The Bio editor after the code is added, with blank space where the video goes Select the page's own button, such as Update Bio, to save. Use view at the top left to open the page and see the video.
Your video is on the page. To show something other than a video, see Embed Code from Another Website.