Spatial Predicates analyze geospatial data types to see if they meet specific conditions. A true or false is returned. Overlaps and Contains are examples of predicates. Spatial Measurement Functions return number values that describe a spatial data type's shape, size, angle, rotation, or position. Examples are Length, Perimeter, and Height.
Spatial Functions perform operations on spatial data types and return a spatial data type.
For example, Union joins two spatial data types and returns the combined result as a new spatial data type. 4.Constructor Functions create new spatial data types. For example, Circle is a spatial data type using a point and radius to create the circle. 5.Observer Functions return numbers, objects, or conditions from within a spatial data type. Assemble and Radius are examples of Observer Functions.