XHTML offers six levels of headings, which use the elements <h1> ,<h2> ,<h3> ,<h4> ,<h5> and <h6>. Browsers display the <h1> element as the largest of the six and <h6> as the smallest.
Most browsers display the contents of the <h1> ,<h2> and <h3> elements larger than the default size of text in the document. The content of the <h4> element would be the same size as the default text, and the content of the <h5> and <h6> elements would be smaller unless you instruct them otherwise using CSS.
Heading elements can all carry the universal attributes:
<h1> H1 Text Formatting</h1>
<h2> H2 Heading Display Mode </h2>
<h3> H3 Headeing Display Mode </h3>
<h4> H4 Heading Display Mode </h4>
<h5> H5 Heading Display Mode </h5>
<h6> H6 Heading Display Mode </h6>
Whenever you use the < br / > element, anything following it starts on the next line. The < br / > element is an example of an empty element.you don’t need opening and closing tags, because there is nothing to go in between them.
The < br /> element has a space between the characters br and the forward slash.
Element can carry the following attributes:
<h1> This is the First Line of Heading </h1>
<h2> This is the Second Line of Heading </h2>
<h3> This is Third Line of Heading </h3>