what is the difference between the Window and JWindow classes and Frame and JFrame in java
Window is an AWT class you probably won't need and JWindow is a Swing class that you probably won't need :)
Ok, seriously, here's some info on window differences.
If you are using Swing for a GUI, you will probably only need to use JFrame and JDialog for your top-level window components. The "J" in front of the name indicates a Swing component instead of a heavyweight AWT component.