A geographic information system (GIS), or geographical information system captures, stores, analyzes, manages, and presents data that is linked to location.  GIS  includes mapping software and its application with remote sensing, land surveying, aerial photography, mathematics, photogrammetry, geography, and tools that can be implemented with GIS software.

GIS Software
Geographic information can be accessed, transferred, transformed, overlaid, processed and displayed using numerous software applications. Within industry, commercial offerings from companies such as Autodesk,  Bentley Systems, ESRI, Intergraph, Manifold System, Mapinfo and Smallworld dominate, offering an entire suite of tools.
Projections, coordinate systems and registration
A property ownership map and a soils map might show data at different scales. Map information in a GIS must be manipulated so that it registers, or fits, with information gathered from other maps. Before the digital data can be analyzed, they may have to undergo other manipulations—projection and coordinate conversions

Spatial analysis with GIS
Given the vast range of spatial analysis techniques that have been developed over the past half century, any summary or review can only cover the subject to a limited depth. This is a rapidly changing field, and GIS packages are increasingly including analytical tools as standard built-in facilities or as optional toolsets, add-ins or ‘analysts’.