title: What is Tomcat? A web container or EE container?
body: <p>I am new to java web technology. It is said that java web applications have two containers:</p>
  
  <ul>
  <li>Web container</li>
  <li>EE container</li>
  </ul>
  
  <p>What are these containers? And how do they collaborate?</p>
  
  <p>Some say that Tomcat is a web container, whereas in some places it is said that Tomcat is an application server.What is Tomcat exactly?</p>
  
  <p>If I say <code>web container + EE container = Application server</code> is it correct?</p>