Headings come in various sizes, ranging from <h1> to <h6>, and appear
in boldface.
<h1> is the largest and is often used as the main heading of a page, with
a ``page'' referring to one screen that appears in a WWW browser.
<h2> headings are often used as subheads. The text of <h3> headings
is the same size as the text used in the main body of the HTML document
paragraphs; the text in the <h4> through <h6> headings is smaller
than the regular text in the document.