Check out example codes for "how to change font size in html". It will help you in understanding the concepts better.

Code Example 1

<body>      
         <h1 style="color:red;font-size:40px;">Heading</h1>      
         <p style="color:blue;font-size:18px;">This is demo text</p>    
      </body>

Code Example 2

<span style="font-size:20px;"></span>

Code Example 3

<font size="+2">This is bigger text.</font>

Code Example 4

font-size: 25px;

Code Example 5

font-size:20px;

"default size is : +-16px;"

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