Heading tags are used to create headlines and to separate blocks of text into easy-to-read sections.
Since the words in heading tags are displayed so prominently on webpages, search engines weight them very heavily in determining relevancy and thus search engine ranking.
There are six heading tag levels, numbered from one to six, but search engines give preference to the largest, <h1>, and the second largest, <h2>.
In your source code, heading tags look like this:
<h1>Write Your Headline Here</h1>
The most important keyphrase for the page should be included in the <h1> tag, as near to the beginning as possible. (Note: For best search engine ranking results, that same keyphrase should also be included near the beginning of the <title> tag.)
Use the <h2> tag to separate your webpages into easily readable sections. Each <h2> tag should include a secondary keyphrase that is relevant to the section that follows.
While the <h1> tag should cover the overall topic of the entire page, use <h2> tags for the page's subtopics.
Consider this example, taken from the Copywriting for Search Engines chapter:
<h1>Blood Donation</h1>
Introductory paragraph(s) heavily optimized for blood donation.
<h2>Where to Donate Blood</h2>
Paragraph(s) optimized for the secondary keyphrase donate blood with additional uses of the primary keyphrase blood donation
<h3>Blood Donation Centers</h3>
Paragraph(s) optimized for the secondary keyphrase blood donation centers with additional uses of the secondary keyphrase donate blood and the primary keyphrase blood donation
<h2>How to Organize a Blood Drive</h2>
Paragraph(s) optimized for the secondary keyphrase blood drive with additional uses of the primary keyphrase blood donation
<h3>Blood Drive Tips</h3>
Paragraph(s) optimized for the secondary keyphrase blood drive tips with additional uses of the secondary keyphrase blood drive and the primary keyphrase blood donation
<h3>Blood Drive Posters</h3>
Paragraph(s) optimized for the secondary keyphrase blood drive posters with additional uses of the secondary keyphrase blood drive and the primary keyphrase blood donation
