title: What is the difference between abstract and interface in php?
body: <blockquote>
  <p><strong>Possible Duplicate:</strong><br />
  <a href="https://stackoverflow.com/questions/1913098/php-what-is-the-difference-between-an-interface-and-abstract-class">PHP: What is the difference between an interface and abstract class?</a></p>
  </blockquote>
  
  <p>As far as I understand, a class implements or extends abstract or interface class has to use the default methods. I know we can use implement keyword to use multiple interfaces, but we only can extend 1 abstract. Which one to use in real life project and the difference?</p>