title: Different ways of adding a library to my HTML
body: <p>Is there any important difference between using the following code:</p>
  
  <pre><code>&lt;script&gt;window.jQuery || document.write('&lt;script src="js/vendor/jquery-1.11.0.js"&gt;&lt;\/script&gt;')&lt;/script&gt;
  </code></pre>
  
  <p>or just adding a library with the script tag (the following code):</p>
  
  <pre><code>&lt;script src="js/vendor/jquery-1.11.0.js"&gt;&lt;\/script&gt;
  </code></pre>
  
  <p>to add a library to an HTML?</p>