What is "jdialog"

A dialog window is an independent sub-window, intended to carry a temporary warning in addition to the main window of an application . Most dialog boxes present an error message or warning to the user, but the Jdialog can display images, directory trees or anything compatible with the Swing application that manages them.

Each dialog window is dependent on a component Frame. When that frame is destroyed, so are all of your dependent dialogue windows. When Frame is minimized, its dialogs windows also disappear from the screen. When Frame is restored, its dependent dialogs windows return to the screen. The class Jdialog swing inherits this class behavior Dialog that belongs to the package awt.

References:

How to Make Dialogs

Documentation by Jdialog