Check out example codes for "html set icon". It will help you in understanding the concepts better.

Code Example 1

<link rel="icon" href="http://example.com/favicon.png">

Code Example 2

<link rel="shortcut icon" href="http://sstatic.net/stackoverflow/img/favicon.ico">

Code Example 3

<link rel="shortcut icon" href="/favicon.ico"> 
<link rel="icon" type="image/png" href="/favicon.png" sizes="32x32"> 
<link rel="icon" type="image/png" href="/favicon.png" sizes="96x96"> 
<link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png"> 
<meta name="msapplication-TileColor" content="#ffffff"> 
<meta name="msapplication-TileImage" content="/mstile-144x144.png">

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