IS Software works by combining a visual front-end, a database driven backend, incorporated with extensions that allow references between spatial and attribute data to support spatial analysis. But what doe sthat mean?

Considering the key component of spatial and attribute data first, the database portion of GIS software provides a store for spatial data to allow map rendering. In addition, further database or database table can be incorporated to provide attribute data, growing the scope of related data and allowing for more complex and original spatial analyses. Hence, the database back-end is a collection of spatial and attribute data using RDBMS like SQL Server or MySQL.

The visual front-end is like a reader that displays spatial and attribute data in layers or themes. Each theme represents a specific dataset, which can be toggled to customised what data is visual at any time. The front-end provides the user interface to perform data queries, directly manipulate the maps, perform spatial analysis and produce reports.

The GIS extension can be any collection of GIS specific tools or a GIS engine that provides the front- and back-end capability and GIS functionality. These extensions allow the wide scope of view, selection, editting and many more tools to manipulate your GIS data.

GIS Data & Software Structure

The structure of a GIS incorporating multiple data sources and GIS software would look be as follows:

The diagram could be an example of a GIS used to analyse the environmental impact of transport in an area relative to private economic activity. This is indicated by the sources of data for transport, environment, demographics, employment along with the spatial data.

The visual display of this data is via GIS software, the provides a layered approach to viewing data.

Most GIS take on this structure and it is mostly a question of what extent of data is appropriate for use.