What is a GIS?
GIS is an abbreviation for geographic
information system, which is
computer software that maps and
analyzes geographic data
A GIS links location (spatial or maps) and
database (tabular) information and
enables a person to visualize patterns,
relationships and trends.
What is a GIS? (Continue)
Spatial or Map (Raster or Vector)
This is a vector map… Database (Tabular)
Still Defining GIS
What do you need to use GIS?
A full GIS, or geographic information
PEOPLE Printers, Plotters,
Managers, Technicians, Software
End users, Consumers
GIS software, Database
G software, OS software,
Specifications, Vector, Raster, Images,
Ultimate definition of a GIS
It’s a TOOL.
Oxford Dictionary defines a tool as:
1. Instrument held in the hand and used for
2. Anything used to DO or ACHIEVE
GIS is about DATA, not
Data is information, Knowledge (or
know-how) has to do with the process
of learning, understanding, and
GIS software Free OpenSource Windows Mac OS X Linux BSD Unix Web
Autodesk No Yes No Yes No No Yes
CARIS No Yes No Yes Yes Yes Yes
Chameleon Yes Yes Yes Yes Yes Yes Yes
eica ERDAS IMAGINE Yes No Yes No No No Yes No
ESRI No Yes No Yes No Yes Yes
GRASS Yes Yes Yes Yes Yes Yes Yes via pyWPS
ClarkLabs IDRISI No No Yes No No No No No
Intergraph  No No Yes No No No CLIX Yes
Pitney Bowes MapInfo No Yes No Yes No Yes Yes
UMN MapServer Yes Yes Yes Yes Yes Yes Yes
Caliper Maptitude No No Yes No No No No Yes
MapWindow GIS Yes Yes No No No No No
Oracle Spatial No No Yes Yes Yes No Yes Yes
Flash & AJAX
Orbit GIS home No
PostGIS Yes Yes Yes Yes Yes Yes Yes Yes
Quantum GIS Yes Yes Yes Yes Yes Yes Yes Yes
Smallworld No No Yes No Yes ? Yes Yes
Caliper TransCAD No No Yes No No No No Yes
TerraLib TerraView Yes Yes Yes No Yes No No No
uDIG Yes Yes Yes Yes Yes No No No
The power of a GIS:
Find all the market centres in Kenya that are within a 10km
distance from major roads.
Kenya has more than 1600 towns.
Which ones of them are market centres?
How do I define a major road?
I cannot go and measure, by vehicle or foot, the distance
each town is from the major road – IT WILL TAKE ME
WITH A GIS IT CAN TAKE ME 5 minutes!