From http://www.w3schools.com (Copyright Refsnes Data)
DHTML is about combining HTML, JavaScript, DOM, and CSS.
In this tutorial you have learned that DHTML is only a term used to describe the different combinations of HTML, JavaScript, DOM, and CSS that can be used to create more dynamic web pages.
JavaScript is the standard scripting language for the Internet.
Everyone serious about web development should have a full understanding of JavaScript.
Visit our JavaScript tutorial, and our complete JavaScript reference.
HTML 4 supports the HTML Document Object Model (DOM).
The HTML DOM is the official (standard and browser independent) way to access HTML elements. It works in all browsers.
Only by using the HTML DOM you can make interactive web pages that will work in all modern browsers.
If you are serious about web development, study our HTML DOM tutorial, and our complete HTML DOM reference.
There is no such thing as dynamic CSS.
However, with JavaScript and the HTML DOM you can dynamically change the CSS style of any HTML element.
In this tutorial you have seen that web pages can be made dynamic by using scripts on the client (in the browser).
Web pages can also be made more dynamic by using scripts on the server.
With server scripting you can edit, add, or change any web page content. You can respond to data submitted from HTML forms, access data or databases and return the results to a browser, and customize pages for individual users.
At W3Schools you can study the following server side scripting tutorials:
From http://www.w3schools.com (Copyright Refsnes Data)