title: observer pattern vs MVC
body: <p>I am wondering what are the differences between an observer pattern and MVC.
  I have some experiences writing MVC program in Java at school, but no experience with observer pattern. (someone told me that observer pattern means I used the Observer class in Java... I don't think that's a good answer.)</p>
  
  <p>Please help me with the following questions, thanks a lottttt.</p>
  
  <ol>
  <li><p>What is the difference between them? The observer pattern does not uses a separate class for controllers?</p></li>
  <li><p>What is the relationship between observer pattern and MVC?
  I heard two different versions.</p>
  
  <ul>
  <li>First version is that, MVC is an architecture and Observer Pattern is an design pattern. They look similar because MVC uses the observer pattern.</li>
  <li>Second version is that, observer pattern and MVC is two different design patterns.</li>
  </ul></li>
  <li><p>Is it possible to use only one of them? If so, in what cases, you uses one over the other and why?</p></li>
  </ol>