Unit Set

A set which typically uses one large scenic item such as a platform or group of platforms to represent all the locations for a production. For Instance many of Shakespeare's plays have scenes that take place in a wide variety of places. to overcome budget and facility limitations ad Director and scenic designer may choose to produce Hamlet on a single large platform, with various smaller scenic elements being carried in by actors or stagehands at various times throughout the action of a play.
Units sets can be cost effective not only from a budget standpoint but from a time stand point as well as, quite often, scene changes flow much more smoothly through the action of the play.