What is a GIS?

A GIS is a tool for making and using spatial information. Among the many definitions of GIS, we choose: A GIS is a computer-based system to aid in the collection, maintenance, storage, analysis, output, and distribution of spatial information. When used wisely, GIS can help us livehealthier, wealthier, and safer lives. Each GIS user may decide what features and attributes are important. For example, forests are good for us. They may protect water supplies, yield wood, harbor wildlife,and provide space to recreate.We are concerned about the level of harvest, the adjacent land use, pollution from nearby industries, or where forests burn. Informed management requires knowledge of all these related factors and, perhaps above all, the spatial arrangement of these factors. Buffer strips near rivers may protect water supplies,clearings may prevent the spread of fire, and polluters upwind may harm our forests. A GIS helps us analyze these spatial interactions, and is also particularly useful at displaying spatial data and analysis. A GIS is often the only way to solve spatially-related problems.