Geographic Information System (GIS) is one of the best tools currently available for managing geographic information. It is estimated that about 85% of the information managed by cities and counties is geographically referenced (i.e. located on the Earth) in some way, such as the location of a building shown on a map. Examples of geographic information are addresses, parcels, school district boundaries, a road network, land use patterns, buildings, and utility locations.
The definition of GIS varies depending on specific applications, but generally it is described as a computer-based system with the ability to store, retrieve, modify, analyze, and represent geographic data as an useful information. A GIS links map information (spatial data) with tabular information (stored in a relational database) about particular features on the map.
Many government agencies, are utilizing GIS because it offers a way of understanding and dealing with complex spatial problems by organizing the data, viewing their spatial associations, performing multiple analyses, and synthesizing results into maps and reports.
