Here the code and the output, which is self explanatory.
Heading Tag:
<HTML>
<BODY>
<H1>Heading</H1>
<H2>Heading</H2>
<H3>Heading</H3>
<H4>Heading</H4>
<H5>Heading</H5>
<H6>Heading</H6>
</BODY>
</HTML>
Other Formatting Tag:
<HTML>
<BODY>
<BIG>Big Text</BIG><BR>
<EM>Emphasized Text</EM><BR>
<SMALL>Small Text</SMALL><BR>
<STRONG>Strong Text</STRONG><BR>
This is <SUB> subscript </SUB><BR>
This is <SUP>superscript</SUP><BR>
I am <DEL>26</DEL> <INS>27</INS>
</BODY>
</HTML>
