HyperText Markup Language.
The language World Wide Web hypertext documents are written in. It features hyperlinks where you click on a string of highlighted text and access a new document which can be at that site or anywhere else in the world. The new document is located by it's URL and can be another HTML document, pictures, sound files, etc. HTML is designed to be platform independent, not bound to a particular hardware or software environment. It is currently being designed by WWW3. Advanced HTML is easily picked up by viewing the source code behind whatever page tickles your fancy - answering "how did they do that?" is just a drop-down menu away on your browser.