title: What is the difference between CloseableHttpClient and HttpClient in Apache HttpClient API?
body: <p>I'm studying an application developed by our company. It uses the Apache HttpClient library. In the source code it uses the <code>HttpClient</code> class to create instances to connect to a server. </p>
  
  <p>I want to learn about Apache HttpClient and I've gone trough <a href="http://hc.apache.org/httpcomponents-client-ga/examples.html">this set of examples</a>. All the examples use <code>CloseableHttpClient</code> instead of <code>HttpClient</code>. So I think <code>CloseableHttpClient</code> is an extended version of <code>HttpClient</code>. If this is the case I have two questions:</p>
  
  <ul>
  <li>What is the difference between these two?</li>
  <li>Which class is recommended to use for my new development?</li>
  </ul>