Dynamic HTML/Ajax

Dynamic HTML is a client side technology (nearly universally based on JavaScript) to increase the interactivity of a web site above a basic static page. Common uses of Dynamic HTML include drop-down menus, simple animations, and input field validation.

Ajax (Asynchronous JavaScript and XML) is a combination of technologies which integrates server-side and client-side tasks to make a web site seem more responsive. While the name Ajax and the broad use of these technologies used in this way is relatively new, the underlying technologies are mature.