All technologies used on the web that are to become a worldwide standard have to be agreed by the World Wide Web Consortium (W3C). DHTML or Dynamic HTML is not one of these standards or a standalone technology. DHTML means using the web standards JavaScript, CSS and HTML together to create web pages that appear to be dynamic. They only appear to be dynamic as they change their look without having to reload. Real dynamic pages on the other hand retrieve and send data from and to the backend or other systems. (This is something you can do nowadays without reloading the full page as well, using XHR or AJAX but we won't talk about that here as it is a different topic)

Making pages dynamic in the sense of making the user interface slicker and avoiding page reloads is a good thing, however as DHTML never really matured it wasn't done properly. This is partly because of the browser environment at that time. At the high time of DHTML browsers didn't support the standard Document Object Model (DOM) but had own implementations of the same idea.