The possible conditions, parameters, and specifications with which an information system or system component can be described or arranged.
NIST SP 800-128
Step in system design; for example, selecting functional units, assigning their locations, and defining their interconnections.
NIST SP 800-82 Rev. 2 under Configuration (of a system or device)
The selection of one of the sets of possible combinations of features of a system.
(ITSEC Ver. 1.2)