What Is GIS?
A Geographic Information System is an automated system that provides for the capture, storage, display, manipulation, and output of spatially referenced data.
In a GIS model:
- Data is organized by layers
- Each layer represents a common feature (transportation, soils, elevation...)
- Layers are bound by a common reference system
See the coverages that the Lower Platte North NRD has in its GIS here.
For a general overview of GIS and how it is applied in different industries check out ESRI's About GIS.
The U.S. Geological also offers an informative page on Geographic Information Systems.