PopupFactory, as the name implies, is used to obtain instances of Popups. Popups are used to display a Component above all other Components in a particular containment hierarchy. The general contract is that once you have obtained a Popup from a PopupFactory, you must invoke hide on the Popup. The typical usage is:

   PopupFactory factory = PopupFactory.getSharedInstance();
   Popup popup = factory.getPopup(owner, contents, x, y);
   popup.show();
   ...
   popup.hide();