Use Headings to Show Hierarchical Relationships of Content

Summary

Headings (h1-h6) should have a semantic meaning.
- Semantic meaning means that the tag you use around content indicates the type of information it contains.
- Should not be used to simply increase the font size.
  - Use CSS.
Each page should include only one h1 element.

Final Code

<h1>How to Become a Ninja</h1>
<main>
  <h2>Learn the Art of Moving Stealthily</h2>
  <h3>How to Hide in Plain Sight</h3>
  <h3>How to Climb a Wall</h3>

  <h2>Learn the Art of Battle</h2>
  <h3>How to Strengthen your Body</h3>
  <h3>How to Fight like a Ninja</h3>

  <h2>Learn the Art of Living with Honor</h2>
  <h3>How to Breathe Properly</h3>
  <h3>How to Simplify your Life</h3>
</main>