(1) In the GDDM function, a rectangular area within the picture space that defines where the output of the current page appears on the work station.
(2) That portion of a partition or usable area defined for display of data to the operator. The viewport has a predefined size and position on the screen and is related to a presentation space through a specified window. See also presentation space.
(3) In BMS, that part of a screen that is allocated to a partition. See also partition.