Geographic Information System (GIS)

A geographic information system (GIS), is an information system for capturing, storing, analyzing, managing and presenting data which are spatially referenced (linked to location) in the form of maps, globes, reports, and charts.

Modern GIS technologies use digital information, for which various digitized data creation methods are used. The most common method of data creation is digitization, where a hard copy map or survey plan is transferred into a digital medium through the use of a computer-aided design (CAD) program, and geo-referencing capabilities.

A GIS can also convert existing digital information, which may not yet be in map form, into forms it can recognize and use. For example, digital satellite images generated through remote sensing can be analyzed to produce a map-like layer of digital information about vegetative covers, land use, soil types, city layout, roads and many others.

A GIS can be viewed in three ways:

The Database View: A GIS is a geographic database (or geodatabase) of the world. Fundamentally, a GIS is based on a structured database that describes the world in geographic terms.

GIS Data View

The Map View: The Map View is based on Geovisualization, which refers to "working with maps and other views of the geographic information including interactive maps, 3D scenes, summary charts and tables, time-based views, and schematic views of network relationships."

GIS Map View

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."