********
Glossary
********

Geometry
   The shape that is associated with a feature.  In many GIS systems the a feature can only have a single geometry type,
   where the type is constrained to being the same for the entire dataset.

Dataset
   A table containing features.

Empty
   It is known that a geometry does not exist within the feature's domaine.  Normally only needed for attribute tables
   with multiple geometry columns.

Null
   The geometry is unknown.  It may or may not be empty depending on the dataset.

API
   Application Programming Interface.  Often a set of classes (objects) and sub-classes that can be instantiated in a selection of computer languages.