Indicates the beginning and the end of the HTML document. Most browsers display each level header in a different size with H1 being the largest.
Headers are on a line by themselves with a blank line above and below.
No paragraph tags are needed with header tags. Indicate a paragraph. Inserts a blank line before and after the paragraph. Good for explanations of codes, or notes for the page editors. It may become obsolete in future versions, consider using style sheets instead.