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<html> <!--called root tag-->
<head> <!--contains meta information of page-->
<title><!--contains title of page-->
it is first page
</title>
</head>
<body><!--contents part-->
<h2>We are talking about external link</h2>
<a href="http://www.google.com">goto google.com</a>
<!--it is called external link-->
<!-- we have to give website where we want to switch -->
</body>
</html>