The GUI Designer's Palette tool window can contain groups which can be used as a means of organizing GUI components. Each Group can contain one or more GUI components, and can optionally display a custom icon for each component.
Initially, there are 2 default groups: Swing that contains the default
javax.swing components, and Palette that contains one default node: Non-Palette Component. You can create other Groups for components from your libraries of GUI components and forms.