So you’ve made a video, and you want to include it on your website. Should you ‘self host’ it, or embed it from a third-party video site such as YouTube? And what does your approach do for your site’s SEO?
By ‘self hosting’ the video, I’m referring to having it on any server where it wouldn’t be accessed independently (something like Amazon S3). Then the only place it appears would be your website, and everything is under your control. The main SEO reason to do this would be if you’re targeting appearing directly in the Google search results with the video, and you want the visits to go to your website. If you host the video on YouTube, Vimeo etc., it’s those sites which will appear in the search results, even if you’ve embedded their video on your site.
Another advantage of ‘self hosting’ the video is that you avoid the risk of adverts appearing, and anything else which YouTube has to offer. However, I’d still normally recommend putting the video on YouTube and embedding it from there. Like it or not, YouTube’s site and app are where most people find video; they search there, and they watch lots of suggested related videos there.
In terms of SEO, embedding a YouTube video on your website probably doesn’t make much difference, either to your page or to the video on YouTube. I’d guess that Google will note the link, and may pass context in either or both directions, but you should have set up both your web page and the YouTube page with the relevant keywords anyway. Perhaps the only SEO advantage of having a video on your web page is unrelated to where it’s hosted; a video increases engagement with the page, and that’s a good thing for SEO.