Geospatial data units, commonly refered to as features, can be related to one another in one of three fundamental ways. Mutually exclusive meaning that there is no space common to both features, partially inclusive meaning that each feature overlaps the other but not entirely. They occupy space that is both common and unique to one another. And all inclusive meaning one feature si defined entirely within the bounds of the other. Points, lines and polygons can relate to polygons in this way. Yet lines can only intersect one another. Points can be part of a line and can be included in a polygon or be part of the polygons bound definition.