What is GIS?
Geography is information about the earth's surface and the objects found on it, as well as a framework for organizing knowledge. GIS is a technology that manages, analyzes, and disseminates geographic knowledge.
The Case for Geography
Geography isn't just an academic subject, it's a serious discipline with multibillion dollar implications for businesses and governments. Choosing sites, targeting market segments, planning distribution networks, responding to emergencies, or redrawing country boundaries—all of these problems involve questions of geography.Learn more about why Geography Matters [white paper, PDF-319 KB].
Geographic Information Systems
GIS is a technology that is used to view and analyze data from a geographic perspective. The technology is a piece of an organization's overall information system framework.
GIS links location to information (such as people to addresses, buildings to parcels, or streets within a network) and layers that information to give you a better understanding of how it all interrelates. You choose what layers to combine based on your purpose.Learn more about the technology.
Within a few hours of the destruction of Space Shuttle Columbia, GIS accurately modeled the shuttle's debris location and distribution. Learn more.
Three Views of a GIS
A GIS is most often associated with maps. A map, however, is only one of three ways a GIS can be used to work with geographic information. These three ways are:
The Database View: A GIS is a unique kind of database of the world—a geographic database (geodatabase). It is an "Information System for Geography." Fundamentally, a GIS is based on a structured database that describes the world in geographic terms. Learn more.
The Map View: A GIS is a set of intelligent maps and other views that show features and feature relationships on the earth's surface. Maps of the underlying geographic information can be constructed and used as "windows into the database" to support queries, analysis, and editing of the information. This is called geovisualization. Learn more.
The Model View: A GIS is a set of information transformation tools that derive new geographic datasets from existing datasets. These geoprocessing functions take information from existing datasets, apply analytic functions, and write results into new derived datasets. Learn more.
Together, these three views are critical parts of an intelligent GIS and are used at varying levels in all GIS applications.