The HyperText Markup Language has been around since the beginning of the World Wide Web. It is the basis of most Web sites.
HTML is a language that uses text and a defined set of commands (known as tags) to create most of what you see on a World Wide Web page. The tags can serve two distinct functions: They either "tell" the text how to behave (bold, italic, etc.), or make the text act as a command to insert a link, picture, or sound onto your page.
According to the World Wide Web Consortium (W3C), "HTML is the lingua franca for publishing hypertext on the World Wide Web. It is a non-proprietary format based upon SGML, and can be created and processed by a wide range of tools, from simple plain text editors � you type it in from scratch � to sophisticated WYSIWYG authoring tools. HTML uses tags such as
</h1> to structure text into headings, paragraphs, lists, hypertext links etc."