A Geographic Information System can be defined 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 (Lo, 2002).  The main objective of a GIS is to add value to spatial data by allowing it to be organized and viewed efficiently, by integrating them with other data, by analysis, and by creation of new data.

Geographic Information Systems are designed for data pertaining to real-world features or phenomenon described in terms of location, also known as geographic data.  This data must follow several criteria: they must be connected with an accepted geographical coordinate system of the Earth’s surface, they must be represented on a geographic scale, and they should describe the spatial interrelations with each other which describe how they are linked together.

One example of the use of a GIS is in the real estate market.  A company in this field that owns various land parcels throughout a city could create a GIS of those properties.  All the information the company had on its properties would be linked to a spatial database (a map of the city and their properties).  Then someone interested in a good location for a new store, in a certain region, could query the area for parcels of land based on certain specifications such as: How far is the parcel from a major intersection? How populated is the area around it? How much will it cost? How is it zoned? Is there proper drainage for construction on the site?, etc. The company could enter those parameters into the GIS, and then would be able to print out a highlighted map of the properties meeting those specifications.