(1) An environment, in one or more CECs, that supports more than one VSE image. See also VSE image.
(2) A physical processing system (such as an IBM 3090) that is partitioned into one or more processors, where each processor is capable of running under the control of a single VSE operating system.
(3) A physical processing system, using the processor resource/systems manager (PR/SM), divided into multiple logical partitions, with each logical partition (LP) operating a copy of VSE. See also Processor Resource/Systems Manager.