an organized collection of computer hardware, software, spatial data, and personnel. A GIS is designed to efficiently capture, store, update, manipulate, analyze, model, display, query, and map all forms of geographically referenced information. GIS software incorporates the graphics functionality of Computer Aided Drafting (CAD) software with the data management, manipulation, analysis, and modeling features of Relational DataBase Management Systems (RDBMSs). Due to the intense graphics manipulations required by GIS functions, GIS originally evolved in the powerful workstation computing environment. Recent advances in desktop computing technologies have allowed GIS to migrate into the PC arena as well. Certain complex spatial operations are possible with a GIS that would be very difficult, time consuming, and/or impracticable otherwise.