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Data Formats

There are generally three basic types of files when it comes to geospatial data:

1) Attribute (Tabular) Data: This data is descriptive and can be directly linked to features. It is compiled and collected at different levels of measurement (i.e. Census Subdivisions, Postal Codes, etc.), then it can be combined with other data sets to display information on a map.

2) Image Data: Image data can range from scanned maps to aerial photographs and satellite images.

3) Cartographic (Map) Data: This data contains information on the shape and location of geographic features. Features are represented by points, lines and polygons.


What is GIS?

"A GIS is a computer system capable of capturing, storing, analyzing, and displaying geographically referenced information; that is, data identified according to location." (USGS, 2007)

"A geographic information system (GIS) integrates hardware, software, and data for capturing, managing, analyzing, and displaying all forms of geographically referenced information." (ESRI, 2008)

There are several definitions for GIS, common to all definitions is the "spatial" or "geographically referenced" element. Data must be associated with a location in order to be portrayed on a map. For more detailed explanations of GIS explore some of the helpful links.

Helpful Links

What is GIS: ESRI: This site helps define GIS as well as explaining some of the general models of a GIS, applications and an index to dictionaries, periodicals and dictionaries.

ESRI’s ArcGIS Desktop Online Help: ESRI: This online help site contains the same information that comes in the help files with the software. Many how to questions are answered on this site. :The GIS EncylopediaESRI: This GIS-centric encyclopedia serves as a repository for factual, unbiased GIS seeks to involve the GIS community in an ongoing process of creation and collaboration of conceptual GIS information.

Geographic Information Systems: USGS: This site provides more explanations to help understand, what GIS is, how it works, some useful applications, and a variety of other GIS related information.

GIS Lounge: DM Geographics: This site is a great resource for a variety of information pertaining to GIS.