Common File Formats for Spatial Data. Formats in bold are very common and an every day part of GIS life.
| Name of Format | Sample File Name | Description |
| Vector (& Sometimes Raster) Data | ||
| Arc Export | Wetlands.E00 | This is a proprietary file format used to distribute Arc/Info datasets. Topology and attributes are properly maintained in this format. |
| Arc Shape | See description | Shape files are used in ArcView. A shape file actually consists of 3-6 separate files (ending in .dbf, .shx, .shp, .sbx, .sbn, etc.) and might be delivered as a single ZIP'ped file. Shape files do not have topology. |
| Zip | Wetlands.ZIP | One or more files compressed and consolidated into a single binary file. Use WinZIP to uncompress and extract the contents of the ZIP file. |
| Geodatabase | Town.MDB | One or more feature classes and raster datasets stored in a Microsoft Access database file. |
| Self Extracting Zip | Wetlands.EXE | The same as above, but does not require WINZIP to uncompress and extract the contents. Simply double click on the EXE file and it will unzip itself. |
| MIF | Wetlands.MIF | Map InFo vector format. MapInfo is a popular GIS software product. |
| DXF | Wetlands.DXF | These are drawing files from CAD systems. |
| DWG | Wetlands.DWG | These are drawing files from CAD systems. |
| DGN | Wetlands.DGN | A file format used by some CAD systems (e.g., Design files from Bentley MicroStation) |
| TIGER | TIGER files contain the data from our national censuses. | |
| VPF | Wetlands.VPF | Vector Product Format is commonly used in military applications. |
| DLG | Wetlands.DLG | Digital Line Graph file format is common on some government web systems and and is a way to move data from one GIS system to another. |
| SDTS | Wetlands.SDTS | The Spatial Data Transfer Standard format is designed to be the single, standard file format for distributing spatial data. The USGS uses SDTS as a common format already. |
| Image Data | ||
| TIFF | Wetlands.TIF | An image file format. The resolution can be very good and the image can be georeferenced (meaning that you can overlay other GIS data on top). The georeferencing often accompanies the TIF file as a second file called the TIFF world file and carries an extension like .tfw. TIFF files can be very large, there is little compression. |
| GIFF | Wetlands.GIF | A common format for image data. GIF does not support georegistration. Image resolution can be excellent and file sizes modest. |
| JPEG | Wetlands.JPG | A common format for image data. JPEG can support georegistration. Image resolution can be excellent and file sizes can be quite small. JPEG compresses images nicely but there can be some loss of resolution. |
| SID | Wetlands.SID | A very efficient compression format for image data. Many GIS data viewers can directly read images compressed using "Mr. SID" compression tools. |
| Raster Data | ||
| DEM | Elevation.DEM | Topographic data sometimes come as DEM's -- Digital Elevation Models -- a format used by USGS. |
| LAN | Wetlands.LAN | A file format used by Erdas image processing software. |
| IMG | Wetlands.IMG | Erdas Imagine uses this format for satellite and other image data. |
| BIL | Wetlands.BIL | Band Interleaved format is a common format for distributing satellite image data. |
| BSQ | Wetlands.BSQ | Band SeQuential format is a common format for distributing satellite image data. |
Miscellaneous Formats |
||
| VRML | Paris.VRML | Virtual Reality Markup Language -- a web-based format for viewing 3-D animations. Frequently used for displaying fly-over animations in GIS and manipulating 3-D renderings of spatial data. |
| ArcMap Project | TOWN.MXD | A file containing an ArcMap project document. |