In Section 11.5, you learned that information about the event that occurs when the user presses Enter in a text field is stored in an ActionEvent object. Many different types of events can occur when the user interacts with a GUI. The information about any GUI event that occurs is stored in an object of a class that extends AWTEvent. Figure 11.11 illustrates a hierarchy containing many event classes from the package java.awt.event. Some of these are discussed in this chapter and Chapter 22. These event types are used with both AWT and Swing components. Additional event types that are specific to Swing GUI components are declared in package javax.swing.event.