A GIS ( Geographic Information System ) is a computer system capable of assembling, storing, manipulating and displaying geographically referenced information, i.e., data identified according to their locations. Practitioners also regard the total GIS as including operating personnel and the data that go into the system.
One of the most important aspect of GIS is the ability to relate two discrete data sets to create a completely new data set, displayed in the form of a map.
"BUSINESS GEOGRAPHICS", is probably the fastest growing area of GIS applications. For example Data showing Pepsi ordered from a chain of shops in an area can be overlaid on data showing number of children per family in that area, creating a new map color coded by number of Pepsi sold per child per family. The Pepsi chain would then look for areas similar in family size to those that showed the highest average numbers of Pepsi ordered when deciding where to locate new shops.
Other commonly applications are for tax mapping, natural resources and emergency services.