Here are examples of each of the heading tags, followed by a paragraph of text (so that you can see how much space each heading tag creates below itself).

<h1>Heading One -- H1</h1>
<p>Here is a paragraph of text.</p>

Here is what this example looks like in your browser:

Heading One -- H1

Here is a paragraph of text.

<h2>Heading Two -- H2</h2>
<p>Here is a paragraph of text.</p>

Here is what this example looks like in your browser:

Heading Two -- H2

Here is a paragraph of text.

<h3>Heading Three -- H3</h3>
<p>Here is a paragraph of text.</p>

Here is what this example looks like in your browser:

Heading Three -- H3

Here is a paragraph of text.

<h4>Heading Four -- H4</h4>
<p>Here is a paragraph of text.</p>

Here is what this example looks like in your browser:

Heading Four -- H4

Here is a paragraph of text.

<h5>Heading Five -- H5</h5>
<p>Here is a paragraph of text.</p>

Here is what this example looks like in your browser:

Heading Five -- H5

Here is a paragraph of text.

<h6>Heading Six -- H6</h6>
<p>Here is a paragraph of text.</p>

Here is what this example looks like in your browser:

Heading Six -- H6

Here is a paragraph of text.