Adopting the convention of upper-casing the commands makes them easier to see in your HTML pages. The header contains information that may be used by the WWW browser, while the body of the WWW page contains the content to be displayed by the browser. Header - the header contains information that may be used by the browser. It is good form to include a header in your document, even if it only contains your document's title. The body - this is the content of your page that the WWW browser application will display.
Headings are automatically boldfaced, and begin at the left side of the page.
In addition, most browsers will accept a start paragraph tag without an end tag. Emphasize text using bold, italic and font size changes. The default font size is 3. One or more characters may be changed.