A geographic information system (GIS) is a computerized system for creating and analyzing maps using digital data. GIS technology does more than create lines or figures on a screen or paper. It creates "smart maps" -- meaning that it's possible to answer questions using various data overlays. For example: Is there any vacant land within 2 miles of an interstate in a particular community? How many residential parcels are located in a particular census block? What land uses are there along a particular bus route? Which industries may contribute to the pollution in a wetland or river?
GIS is not just software -- it also involves people, data and procedures. GIS requires accurate geographic and tabular datasets to perform analysis. In addition, people with skills in computers and geography are needed to create, analyze and manage geographic datasets. Effective procedures are essential for a GIS to function successfully -- for example, rules for data collection and maintenance. GIS is a useful tool to answer geographic-based questions.