What is a GIS?

A Geographic Information System, or GIS, is an organized collection of computer hardware, software, geographic data, and personnel designed to efficiently capture, store, update, manipulate, analyze, and display all forms of geographically referenced information. Or, in simple terms:

A computer system capable of holding and using data describing places on the earth's surface.

Many computer programs, such as spreadsheets, statistics packages or drafting packages can handle simple geographic or spatial data, but this does not necessarily make them a GIS. A true GIS links spatial data with geographic information about a particular feature on the map. For example, the outline that represents an agricultural field on a map doesn't tell you much about the field except its location. To find out the field's acreage or crop type, you must query the database. Using the information stored in the database, you could create a display symbolizing the agricultural fields according to the type of information that needs to be shown.

In short, a GIS doesn't hold maps or pictures - it holds a database. The database concept is central to a GIS and is the main difference between a GIS and drafting or computer mapping systems, which can only produce a good graphic output. All contemporary geographic information systems incorporate a database management system.

GIS is not......

.....simply a computer system for making maps, although it can create maps at different scales, in different projections, and with different colors. A GIS is an analytical tool. The major advantage of a GIS is that it allows you to identify the spatial relationship between map features. A GIS does not store a map in any conventional sense; nor does it store a particular image or view of a geographic area. Instead, a GIS stores the data from which you can draw a desired view to suit a particular purpose.


For more information and free GIS software follow the links below: