title: HTML code with curly braces
body: <p>I have recently seen one HTML page.The code is embed with curly braces.Values for tags and loops are closed by curly braces.</p>
  
  <pre><code>            {% if authenticated %}
              &lt;h1&gt;Current User&lt;/h1&gt;
              &lt;p&gt;{{user}}&lt;/p&gt;
              {% else %}
              &lt;h1&gt;Current User&lt;/h1&gt;
              &lt;p&gt;None&lt;/p&gt;
              {% endif %} 
  </code></pre>
  
  <p>What is the actaul use of these type of code?</p>
  
  <p>Is HTML embedded with any other language?</p>