Software that creates, manage, analyse, and visualize the geographical parameters is refer as a GIS software. In generally applications for GIS software include the evaluation and analysis of location for new stores, the management of power and gas lines, the creation of maps, route calculations for transport tasks, emergency planning and response, the management of forests, parks. For this different fields of activities there are various software available in the market.
GIS usually provide two different possibilities to represent a geographic phenomenon and are: the raster representation and the vector representation. In the raster representation a regular mesh of cells is used, where every cell records the value of the attribute that describe the phenomenon. In the vector model, which is commonly used to store objects that are spatially discrete.
Open source GIS software is a type of “free” software to be accessed, used or modified by their user groups and developers. Like basic desktop GIS software, remote sensing software, 3D visualization tools, others GIS software (including Web mapping servers and clients, spatial programming tools and libraries, and spatial databases).