The QGIS (Quantum GIS) is free and open source GIS (Geographic Information System) software. QGIS offers many common GIS functionalities provided by core features and plugins. We can visualize, create, edit, manage and export geo-spatial data using QGIS. By exploration of GIS data many types of analysis can be performed. Further many types of very useful maps can be created. QGIS was first developed by Gary Sherman in early 2002 using C++ language. Later it became an incubator project of the Open Source Geospatial Foundation in 2007 (Source: OSGeo Annual Report).
Version 1.0 was released in January 2009 (Sutton et al, 2009). QGIS supports both raster and vetcor data. QGIS supports shapefiles, coverages, personal geodatabases, dxf, MapInfo, PostGIS, and other formats and multiple formats of raster images area supported. QGIS integrates with other open-source GIS packages, including PostGIS, GRASS GIS, and MapServer. Plugins written in Python or C++ extend QGIS's capabilities. Plugins can geocode using the Google Geocoding API, perform geoprocessing functions, which are similar to the standard tools found in ArcGIS, and interface with PostgreSQL/PostGIS, SpatiaLite and MySQL databases (Source: wiki QGIS). The QGIS also have QGIS browser and QGIS Server applications. Both of them use same code for data access but come with different front-end interfaces. The QGIS browser is designed to manage geospatial data sets.