A simple "to-do list" application, using client-side HTML, CSS, and Javascript only. Rather than using any external APIs, backends, or databases, this application stores its data locally. In this case, the page does not refresh or reload physically and has no links that go to other pages. If a link is clicked (or a form is submitted), the content of the page disappears, and new content is loaded in its place, all without actually redirecting the user.