<h1>This is heading 1</h1>
<h2>This is heading 2</h2>
<h3>This is heading 3</h3>
<h4>This is heading 4</h4>
<h5>This is heading 5</h5>
<h6>This is heading 6</h6>

<p>Use heading tags only for headings. Don't use them just to make something bold. Use other tags for that.</p>

</body>
</html>

Copy it in your Note-Pad and save it as an htm or an html file and view it in your Default Browser.