>(these may in fact be two separate topics). Yes. Here's one way to think about it. Imagine a traditional webpage. It renders to HTML. If you refetch it, you

>(these may in fact be two separate topics). Yes. Here's one way to think about it. Imagine a traditional webpage. It renders to HTML. If you refetch it, you get new HTML. You can't simply "merge" two HTMLs on top of each other, so if you were to "update" document.body.innerHTML to the new result, you'd blow away focus, selection, etc. Now imagine the server sent "virtual DOM" in the response instead. React knows how to "merge" such updates into the tree without destroying it. This is what React has been doing all along, right? So this is why we can refetch the Server tree, and show the result without blowing away the Client state inside. Now, this virtual DOM tree contains things like divs (with their props) or references to Client Components (e.g. "module number 5 in bundle called chunk3.js") with their props. These are the things that need to be serializable. But they're only passed from Server to Client, not back. Think of them as the same role as HTML attributes.