not so familiar with ASP.NET, but yeah that sounds about right. The key is it runs in the browser itself, rather than being a bundle that's compiled and moved around at build or run time.

you take all your standard html5 stuff, bundle it in one file, and serve that to any client that wants a video player. You can, of course, play minification games or whatever to reduce the number of files - but the pure form is, one include == one component.

I was just going to write it's like ASP.NET Web Forms User Controls. Only that was server-driven.