The document provides information about HTML markup language. It begins with an overview of common HTML tags like <body>, <div>, <li>, <head>, <script>, and <html>. It then discusses void elements that do not require closing tags, such as <br>, <img>, and <input>. The document also lists and defines common HTML tags including tags for text formatting, lists, images, and page structure. It provides an example of how to use the <img> tag and attributes. Finally, it discusses site structure and previews tutorials for next week on CSS and the CSS Zen Garden website.