Modern browsers support playing video via the
<video> element. Most browsers also have access to webcams via the MediaDevices.getUserMedia() API. But even with those two things combined, we can’t really access and manipulate those pixels directly.
<canvas> from the video itself, which gives us the ability to manipulate and play with those pixels.
Everything you learn here about how to manipulate pixels will give you a foundation to work with images and videos of any kind or any source, not just canvas.