A three-dimensional object is solid rather than flat, because it can be measured in three different directions, usually the height, length, and width.
Three-dimensional artifact or naturally occurring object includes man-made objects such as models, dioramas, games, puzzles, simulations, sculptures and other three-dimensional art works and their reproductions, exhibits, machines, clothing, toys, and stitchery. The category also includes such naturally occurring objects as microscope specimens (or representations of them) and other specimens mounted for viewing. This category includes archival items where the distinguishing features of the format or medium are emphasized.
