What you should already know

Before you continue you should have a basic understanding of the following:

• WWW, HTML and the basics of building Web pages
• CSS
• JavaScript

If you want to study these subjects first, find the tutorials on our Home Page.

DHTML is NOT a W3C Standard

DHTML stands for Dynamic HTML.

DHTML is not a standard defined by the World Wide Web Consortium (W3C). DHTML is a "marketing term" - used by Netscape and Microsoft to describe the new technologies the 4.x generation browsers would support.

DHTML is a combination of technologies used to create dynamic Web sites.

To most people DHTML means a combination of HTML 4.0, Style Sheets and JavaScript.

W3C once said: "Dynamic HTML is a term used by some vendors to describe the combination of HTML, style sheets and scripts that allows documents to be animated."

DHTML Technologies

With DHTML a Web developer can control how to display and position HTML elements in a browser window.

HTML 4.0

With HTML 4.0 all formatting can be moved out of the HTML document and into a separate style sheet. Because HTML 4.0 separates the presentation of the document from its structure, we have total control of presentation layout without messing up the document content.

Cascading Style Sheets (CSS)

With CSS we have a style and layout model for HTML documents.

CSS was a breakthrough in Web design because it allowed developers to control the style and layout of multiple Web pages all at once. As a Web developer you can define a style for each HTML element and apply it to as many Web pages as you want. To make a global change, simply change the style, and all elements in the Web are updated automatically.

The Document Object Model (DOM)

DOM stands for the Document Object Model.

The HTML DOM is the Document Object Model for HTML.

The HTML DOM defines a standard set of objects for HTML, and a standard way to access and manipulate HTML objects.

"The W3C Document Object Model (DOM) is a platform and language neutral interface that allows programs and scripts to dynamically access and update the content, structure, and style of a document".

JavaScript (and VBScript)

Allows you to write code to control all HTML elements.

DHTML technologies in Netscape 4.x and Internet Explorer 4.x:

Note: Problems with coding DHTML technologies WILL occur as long as each browser creates its own proprietary features and technology that is not supported by other browsers. A Web page may look great in one browser and horrible in another.

Dynamic HTML, or DHTML, is an umbrella term for a collection of technologies used together to create interactive and animated web sites by using a combination of a static markup language (such as HTML), a client-side scripting language (such as JavaScript), a presentation definition language (such as CSS), and the Document Object Model. DHTML allows scripting languages to change variables in a web page's definition language, which in turn affects the look and function of otherwise "static" HTML page content, after the page has been fully loaded and during the viewing process. Thus the dynamic characteristic of DHTML is the way it functions while a page is viewed, not in its ability to generate a unique page with each page load. By contrast, a dynamic web page is a broader concept — any web page generated differently for each user, load occurrence, or specific variable values. This includes pages created by client-side scripting, and ones created by server-side scripting (such as PHP, Perl, JSP or ASP.NET) where the web server generates content before sending it to the client.