The study and description of spatial relationships and the connectivity of points in space. A simple object is composed of only one element. Simple objects include: vertex, a unique point which is zero-dimensional; edge, a one-dimensional, straight or curved spatial element; loop, a one-dimensional, continuous object that encloses a two-dimensional object; face, the flat or curved surface bounded by a loop; shell, a three-dimensional surface enclosing a volume; region, a three-dimensional volume. An edge does not include the vertices at its termination, nor a face include its loop, nor a region its shell. Complex objects are composed of more than one simple or other complex object. Disjoint objects do not touch or overlap; objects meet if they share a common boundary; they overlap if they share common space but do not have a common boundary; they cover if they overlap and share a common boundary; they contain if one is wholly within the other without a common boundary. They are equal if they are spatially equivalent. Spatial objects may intersect.