A geographic information system (GIS) is a computer hardware and software information system designed to capture, edit, manage, house, manipulate, analyze, and display georeferenced data. It comprises high-resolution scientific visualization capabilities, large-capacity electronic storage devices, efficient and effective structures for data storage and retrieval, high-volume communication channels, specialized algorithms for data integration and reliability analysis, and specialized query languages. Its reference point is a digital map. The first GIS was developed by the Canadian government and implemented in 1964. A differentiating feature among GISs is whether the underlying map involves a raster or vector surface partitioning. Spatial statistics requires attribute data, a map, and the tagging of each data observation to a location on a map, items furnished by a GIS. A GIS also supplies a practical and useful way to reveal spatial and temporal relationships among data. The UCGIS is an organization whose mission is to serve as an effective unified voice for the community of GIS users. Keywords: geostatistics; kriging; spatial autocorrelation; spatial statistics; statistical software