Web GIS provides a browser based access to spatial information preserving the inherent nature of GIS data model (vector/raster) such as scale, coordinate systems, geometry and attributes while completely safeguarding the original data as such. That means the user will have access to the data for viewing and querying, but will not have the physical access to the data. This is further explained in the Web GIS model of interactive portrayal (Doyle, 1999). This model helps to analyze the various stages of information flow in Web GIS applications. This model suggests different stages of Web GIS; information selection, transformation and presentation. In the final stage the user is sees an image of the requested data.
