Geographic Information Systems (GIS) are by their nature data driven. The data comes in a wide variety of raster and vector formats. Rasters hold raw, continuous data recorded striaght from the real world. An example is Satellite/aerial imagery, this is a commonly held in an open format with broad support, such as GeoTIFF <http://en.wikipedia.org/wiki/GeoTIFF> or GeoJPEG <http://en.wikipedia.org/wiki/JPEG>.
Vector formats<http://en.wikipedia.org/wiki/GIS_file_formats#Vector_formats>hold refined, discrete data, which has been manually traced or otherwise derived other data sources. Examples include building outlines, contours, road routes, pipe networks land land parcels and locations. Vector data is usually traced or derived, at great expense from raster data, to encode business information - as a result it’s usually highly valuable. Unfortunately, there are many GIS vector file formats, and most are proprietary. They can only be used to their full in their native software. Three of the biggest are AutoCAD DXF<http://en.wikipedia.org/wiki/AutoCAD_DXF>, MapInfo TAB <http://en.wikipedia.org/wiki/MapInfo_TAB_format> and ArcGIS Personal Geodatabase <http://en.wikipedia.org/w/index.php?title=Personal_Geodatabase>. One vector format is unique - both an open standard, and in wide use: Shapefile. Texto completo pode ser encontrado no blog *Misspelled nemesis club* http://moreati.org.uk/blog/2009/03/01/shapefile-20-manifesto/ -- http://thusbeginstheweb.blogspot.com/
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