<h1>...<h6> for heading
HTML defines a hierarchy of heading elements, with h1 being the highest ranked.
<!DOCTYPE HTML>
<html>
<head>
<title>Example</title>
</head>
<body>
<h1>H1</h1>
<h2>H2</h2>
<h3>H3</h3>
<h4>H4</h4>
<h5>H5</h5>
<h6>H6</h6>
</body>
</html>