The Abstract Window Toolkit vs. Swing

The Java Development Kit contains two sets of widget- and utility classes for creating simple graphical user-interfaces: the Abstract Window Toolkit or AWT, and the Java Foundation Classes or JFC, or popularly called Swing. Small applications with user-interfaces are often called Applets.
Main features of the AWT are: A tutorial on writing AWT applets can be found at: http://java.sun.com/docs/books/tutorial/applet/index.html".

Main features of Swing are:

A tutorial on writing Swing applets can be found at: http://java.sun.com/docs/books/tutorial/uiswing/index.html.

AWT and Swing have some common properties:

Combining AWT and Swing in a single application or applet often leads to problems because AWT uses heavyweight components and Swing uses lightweight components. AWT places components on top of an application's main window through the window system. Swing draws components on top of the application's main window by itself. When both techniques are mixed, the window system's components, created by AWT, are always shown on top.