The tags h1, h2, h3 and h4 display headings. Level 1 headings (h1) are the most prominent headings, and level 4 headings (h4) are the least prominent. H5 and H6, defined in HTML, aren't used here.
Headings are displayed in a bolder, larger font than normal body text. As a heading is just a special type of Paragraph, the properties of the p tag apply to these too.
See the p element examples of general layout applicable to all paragraphs, including h1 to H4
Some simples headings
<h1>This is the heading</h1> <h2>This is the sub-heading</h2> <p>This is the content</p>