Geographic information systems (GIS) are used in a wide range of academic and applied fields. Simply put, GIS allows you to combine tabular data (e.g. a spreadsheet) with geographic boundaries (e.g. maps).
The library carries a huge number of GIS texts, both in print and online.
ArcGIS 10 Desktop is the latest version of the most widely used GIS product, made by company called Esri. It is a Windows-only suite of programs:
There are also a number of extensions for particular tasks:
Geocode: To create points on a map from street addresses in spreadsheet form
Overlay: To superimpose two or more maps or layers in the same coordinate system, to show the relationships between them
Georeference: To align geographic data (map, layer, etc.) with a given coordinate system, allowing for overlays
Select by location (proximity analysis): To select features according to their relationship in space to other features
Select by attribute: To select features according to their properties (attributes), like querying a database
Buffer: To create a zone around a feature in units of distance or time
Network analysis: To find the distance from a feature travelled along a network (such as roads, public transit) rather than as the crow flies
Join: To attach fields from one table to those of another through an attribute or field common to both tables.
Viewshed analysis: To determine what areas are visible from a particular location.
Adapted from Esri's GIS Dictionary.