YouTube inside your own website?

On the Slack website, there is a small area containing a video. When you click on the video to play it, a fullscreen version launches, and there are many signs the video is coming from YouTube. Interestingly, the URL is still the original one I went to for Slack. It is not a YouTube URL. My question is, how is this done. Is this something YouTube helps with, or is it some slick JavaScript? Thanks

It’s a provided api from youtube: https://support.google.com/youtube/answer/171780?hl=en

Hey, thanks for the reply and help. I will check it out — Phil