A Concept that classifies a Region; the difference between a Region and a Parameter is that regions represent sets of observable values, e.g. the height of a given building, while parameters represent constraints or selections on observable values, e.g. 'VeryHigh'. Therefore, parameters can also be used to constrain regions, e.g. VeryHigh on a subset of values of the Region Height applied to buildings, or to add an external selection criterion , such as measurement units, to regions, e.g. Meter on a subset of values from the Region Length applied to the Region Length applied to roads.