title: The concept of file's owner,first responder, and application delegate in iPhone
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/761814/iphone-interface-builder-and-delegates">iPhone Interface Builder and Delegates</a>  </p>
  </blockquote>
  
  
  
  <p>What is the relationship between these three component in the Objective C / iPhone world? I found that the App Delegate have some relationship with the UI and the variable in code. It match the variable and related UI object on the view. But I found that the File's owner have the outlet called delegate that related to the Application delegate, what is their relationship. Also, the first responder, it seems it just receive some effect only. What's going on between there stuff?</p>