Heading Tags are REALLY important for SEO and need to be used correctly. Treat them as if they are an outline:

This code:

<h1>H1 Tag</h1>
<h2>h2 Tag</h2>
<h3>h3 Tag</h3>

Outputs this:

H1 Tag

H2 Tag

H3 Tag

*Note that we use CSS to make the font size and color, and your h1, h2, or h3 tags may look different on your website.