What is a Geographic Information System or GIS?
NCGIA (1990): GIS can be seen as a system of hardware, software and procedures designed to support the capture, management, manipulation, analysis, modeling, and display of spatially referenced data for solving complex planning and management problems.ESRI (1990): GIS is an organized collection of computer hardware, software, geographical data and personnel designed to efficiently capture, store, update, manipulate, analyze and display all forms of geographically referenced information. ESRI has a site which explains geographic information systems in general terms.