In
Windows and other
GUIs, a dialog box is a small
popup window that displays pertinent
information such asking the
user if they are sure they know what they are doing.
Sky should note that they are called dialog boxes in Gnome as well, so please see What Gnome stole and how. Also the dialog box does provide a two-way form of communication. Dialog boxes often have fields and multiple choice buttons which can be used to communicate back with the application.