You can headings to organize your web into hierarchical levels. Headings also act as separators in a words processing documents. The top heading (H1) actually is the title for your page, i.e.., It is appears in a browser windows at the top of the web page. These are 6 levels of heading.
You can also use a second-level heading (denoted by the H2 tag) to define a major division in your page, and a third level heading (Using the H3 tag) to define a sublevel division with a major division. Most browsers support upto six different levels.
H1> This is a top-level heading /H1>
H2> This is a second-level Heading /H2>
H3> This is a third-level Heading /H3>
H4>This is a fourth-level Heading /H4>
H5> This is a fifth-level Heading /H5>
H6> This is a sixth-level Heading /H6>