Answer 1

The following snippet is part of a lesson in the HTML course. If you haven't joined that course I strongly suggest you to go for it, it's fun!

(Edit)
I see you have joined the HTML course, well, you'll get to this lesson when you start HTML 5 chapter.

<video controls>
<source src="video.mp4" type="video/mp4">
<source src="video.ogg" type="video/ogg">
Video is not supported by your browser
</video>

Next time you need help, please make your question descriptive, don't leave the question detail empty like that.

Hth, cmiiw