To fully grasp the techniques that allows Geographic Information Systems (GIS) to tick is difficult and requires a certain understanding the nature of this technology. At core, GIS is a system that allows data to be analyzed on a location-by-location basis. Of course, this is a heavily simplistic version of the truth, but it serves to allow us to begin to scratch the surface of this complicated system.
How GIS Operates
Any systems such as GIS must be capable of four basic abilities: capture, storage, analysis, and finally, display. In terms of GIS, all information must be captured with location in mind, thus it must utilize some methods of indicating location, such as a coordinate system. Once captured and stored, the potential for analysis is huge, as it is possible to compare locations in terms only limited by the variety of data that is captured.
Further extending this potential is the fact that by correlating various data and analyzing patterns, a plethora of trends, conclusions, and predictions may be formed. For example by comparing various rainfall patterns, and observing changes that may occur, it would be possible to reasonably predict the occurrence of a dry-spell. Of course, it is hardly as easy as it sounds; the analysis methods that are required for the task would be daunting to grasp without proper study.
Still, the continued development of GIS has allowed us to tap into the enormous potential that it offers, with much more yet to come. Unfortunately, for laypeople, as GIS develops, it gets horrendously more complex in nature, but the core idea behind its usage remains pretty much unchanged, though admittedly new functions for it keep surfacing.