Dynamic HTML
Web pages vary greatly in their appearance. Some HTML web documents are merely informative, being no more than heading-laden text. Some Web documents are both informative and interactive, such as HTML documents containing forms and a liberal dose of JavaScript. Magazine-style documents, strewn with images, applets and plugins, and sporting fancy styles, headings, colors and typefaces can be quite impressive visually, especially if backed-up by a good graphic artist. Via a few JavaScript multimedia tricks such as those outlined in Chapter 4, images can add a degree of animation. However, for truly impressive Web pages, nothing beats the possibility of independently animating every single tag in a document and its contents, either in response to user actions, or without the user needing to do anything at all. This possibility is offered by Dynamic HTML.
Client-side JavaScript, with its timing mechanisms and access to host objects that reflect a document's content is absolutely crucial for Dynamic HTML. Viewed from the JavaScript perspective, it is the script writer that creates dynamic behavior in a document that is otherwise just an inactive load of HTML.
As is the case for the Java language, Dynamic HTML is a subject rich in information that really requires a book of its own. Only the most important features are touched on here.