<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<div class="container">
<div class="row">
<h2>Image resizes as width or height of browser increases or decreases</h2><p>try in a seperate html file and test in the browser</p>
</div>
</div>
<img class="center" src="https://www.w3schools.com/css/trolltunga.jpg">
