The document discusses various HTML tags and concepts including:
- Basic HTML tags like <html>, <head>, <title>, <body>
- Formatting tags like <b>, <i>, <u> for bold, italic, underline
- Paragraph tags <p> and line break <br>
- Headings tags <h1> to <h6>
- Attributes for the <body> and <font> tags to control text and background colors
- Hyperlinks using the <a> tag and relative vs absolute links
- The <marquee> tag for animated scrolling text