An Introduction to HTML

It all begins with Hypertext Markup Language (HTML). Even though you may never have to write any HTML code, you should be familiar with it because the server typically translates all scripting languages into pure HTML and then returns all requests in pure HTML.

HTML, a subset of Standard Generalized Markup Language (SGML), conforms to International Standard ISO 8879 and has become the worldwide standard for web publishing. Almost all scripting languages interact with HTML, and many scripting languages include the ability to produce output in HTML. In addition, all browsers display almost any HTML file on any computer using any operating system-no wonder everybody uses it. (Experiences may vary, but exceptions to the preceding statement are rare.)

Note 

HTML is a layout language that displays complex documents. A complex document contains both images and text.This language has only two components: the markup and the content. The markup consists of commands, known as tags, that are processed by the HTML engine. The content is the text or image displayed by the browser. The browser never displays HTML markup. Instead, the markup supplies specific instructions on how to display the content.

Thanks to HTML, users can format and display text and images, send requests to the server, create hyperlinks from one file to another (or one page to another), and accept input from other users.