What is HTML?
The World Wide Web Consortium (W3C.com) defines HTML as the publishing language of the World Wide Web. It's initials stand for Hypertext Markup Language(HTML).
In plain English HTML can do nifty things with TEXT. You can change text into useful stuff by writing instructions with tags. A little program in your browser can read this international (universal) language and make the changes.
Examples are:
This is a new paragraph you are reading now by me using the paragraph tags in the HTML of this page.
With the use of these tags you can also pull some fancy objects into your page. Like pictures, or a Flash movie, or a form where your clients can send you information or order stuff from you, or a shopping cart, or JavaScript and other gadgets. Javascript is a script that you embed (pull in) into your page and it make interactive games appear. It can do alot more and should not be confused with the Java programming language. JavaScript works in your browser, Java runs on your PC by itself and interact with your operating system (Windows most likely).
But wait, there is more! Modern HTML link to style sheets (known as Cascade Style Sheets or CSS to tell it what font to use, what colours, what sizes, where things should go on the page and other instructions to make the page look smicko.
Old HTML used tags to give the browsers these instructions. Microsoft and Netscape developed their own tags in the early days, so that a page which looks good in Internet Explorer may look horrible in Netscape. The W3C (remember them?) are standardising the web with CSS and standard tags. If your page complies with their requirements it is said to be an XHTML page or in HTML5 (the latest) format.
There are even more pages hiding behind the buttons you see down here. Grab a cuppa and a bikkie and get comfortable.