title: Spring AOP target() vs this()
body: <p>From <a href="http://static.springsource.org/spring/docs/3.1.x/spring-framework-reference/html/aop.html">Spring Documentation</a>:</p>
  
  <ul>
  <li><p>any join point (method execution only in Spring AOP) where the proxy 
  implements the AccountService interface:</p>
  
  <pre><code>this(com.xyz.service.AccountService)
  </code></pre></li>
  <li><p>any join point (method execution only in Spring AOP) where the target
  object implements the AccountService interface:</p>
  
  <pre><code>target(com.xyz.service.AccountService)
  </code></pre></li>
  </ul>
  
  <p>I don't understand what "target object" and the expression <code>target(...)</code> mean.</p>
  
  <p>How is <code>target</code> different from <code>this</code>?</p>