Geography Reference
In-Depth Information
Chapter 1 So, what exactly is a GIS?
To most people, what they see as a GIS is in fact just the front-end output layer, such as the
maps produced in Google Maps, or the screen on a TomTom navigation device. The reality
of it all extends far beyond that; the output layer is very often the end result of many
interconnecting programs along with massive amounts of data.
A typical GIS will include desktop applications used to visualize, edit, and manage the data,
several different types of backend databases to store the data, and in many cases a huge
amount of custom written software tools. In fact, GIS is one of the top industries where a
programmer can expect to write a very large amount of custom tooling not available from
other companies.
We'll explore some of the applications in detail soon, but for now we'll continue with the 100-
foot view. A typical GIS processing setup will look something like the following:
Figure 1: Typical GIS processing setup
As you can see in the diagram, the central part is very often the database itself with a huge
number of inputs and processing steps. Finally, the output layers (shown in red) are what
people usually associate with being a GIS.
Based on this, we can see that the database is the center of the universe when it comes to
GIS.
