a first responder if the existing first responder returns TRUE for canResignFirstResponder and the current object returns TRUE for canBecomeFirstResponder ✤ The default for canResignFirstResponder is TRUE and FALSE for canBecomeFirstResponder ✤ InputView is shown when UIResponder becomes FirstResponder (like a keyboard)
for determining the next object in the chain ✤ UIView returns its ViewController if its managed by one, or its superview if not ✤ UIViewController returns the UIWindow ✤ UIWindow returns the AppDelegate ✤ Event will be thrown out if not handled