Set of geometric objects. The following is adapted from Feature Geometry (Topic 1) specification.

A geometric object shall be a combination of a coordinate geometry and a coordinate reference system. In all of the operations, all geometric calculations shall be done in the coordinate reference system of the first geometric object accessed, which is normally the object whose operation is being invoked. Returned objects shall be in the coordinate reference system in which the calculations are done unless explicitly stated otherwise. The interface defined in this package are basically those of set theory. In general a geometric object is a set of geometric points, represented by {@link org.opengis.geometry.DirectPosition}. Object instantiations of geometric objects are {@link org.opengis.geometry.Geometry}. Object instantiations of geometric points, when used as values, are {@link org.opengis.geometry.DirectPosition}s. General set theory operations defined at {@link org.opengis.geometry.Geometry} differentiate further down the class hierarchy depending on whether or not the boundary {@link org.opengis.geometry.DirectPosition} are included as set elements. Subtypes of {@link org.opengis.geometry.primitive.Primitive} do not contain boundary points, while subtypes of {@link org.opengis.geometry.complex.Complex} do.