<body>
<h1 style="color:red;font-size:40px;">Heading</h1>
<p style="color:blue;font-size:18px;">This is demo text</p>
</body><span style="font-size:20px;"></span><!-- relative font size -->
<font size="+2">This is bigger text.</font>
<font size="-1">This is smaller text.</font>
<!-- absolute font size -->
<font size="1">This is really tiny text.</font>font-size:20px;
"default size is : +-16px;"<font size="+2">This is bigger text.</font>