The virtual screen is a non-physical display area allocated to the application by the operating system (or the ACUCOBOL-GT runtime). It is called virtual because not all of the allocated area need be displayed on the physical screen. A window (defined below) is used to frame the virtual screen, and scroll bars are provided, if necessary, to allow the user to navigate to any part of the virtual screen. The application behaves as if the entire virtual screen is always available.
The physical screen, virtual screen, and application window