This document discusses various HTML tags that affect text appearance, including header tags (<H1>-<H6>) that make text larger and bold, the <CENTER> tag to center text, and tags for emphasis like <EM> for italics and <STRONG> for bold. It provides examples of using these tags and recommends using <EM> and <STRONG> over <I> and <B> since browsers can render them differently if a style is not supported. The document concludes with an exercise to use these tags.