GIS at UCD and on the Web: Definitions of GIS
Definition from GIS.com
A geographic information system (GIS) integrates hardware, software, and data for capturing, managing, analyzing, and displaying all forms of geographically referenced information.
GIS allows one to view, understand, question, interpret, and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports, and charts.
A GIS helps one answer questions and solve problems by looking at your data in a way that is quickly understood and easily shared.
Dictionary of GIS terms
Harvard Map Collection
The Introduction to GIS tutorial from the Harvard Map Library consists of a three-part movie accompanied by hands-on exercises.
Part 1, which is below, starts by answering the question "What is a GIS?"
Ordnance Survey Ireland (OSi)
GIS stands for Geographical Information System. A GIS is about processing information to help make an informed decision.
Without actually knowing it the general public and businesses are using GIS on a daily basis. GIS has been used for hundreds of years however, in the past using GIS was a manual process but technology has allowed this to become a digital process.
When Geographical Information (GI) is used in conjunction with location (by using maps), a link is created between diverse datasets that can concern, people, places or things.
Visual information in a GIS system can help it to be more easily understood and explained. For instance, if a council wants feedback on a development plan from residents, showing this information such as schools, parks, planned housing and roads all displayed on a map can help the resident understand the impact the plans will have on them.
University of California, Davis
A geographic information system (GIS) ia a computer-based tool that stores geographically referenced, or geo-referenced, data (i.e., data identified according to their locations) and links it with non-geographic attributes (tabular data about the location) to allow for information processing. In addition to helping map your data,
GIS software allows you to see, explore, and analyze data by location, revealing hidden patterns and trends that are not readily apparent from spreadsheets or statistical packages.
This description is from: http://guides.lib.ucdavis.edu/Maps_GIS