A Geographical Information System (GIS) is a computer system that integrates spatial data with its associated tabular records. One example of this would be a parcel layer with its associated information such as owner, acerage, block number, parcel number, etc. Practically everything related to the spatial data can be stored as an attribute in the layer within the GIS. Having all this data stored in a GIS provides an array of tools for query and analysis which can be used throughout many different specialties such as environmental science, marketing, crime trend analysis, asset management, utilities and infrastructure.
In combining information from multiple layers you can see trends, discover relationships, and perform analyses. The accessibility of all this information in one place helps organisations make more informed decisions.
User-friendly mapping interfaces, often delivered over the web, gives non-specialists quick access to the information they need in an accessible format. Analysts can use the system to run powerful spatial queries to model scenarios and answer questions such as "What could happen to properties in these coastal areas if the sea level rises by 0.5 meters?" or "What is the best undeveloped site location available on the island that meets my minimum criteria for size, planning zone classification, and terrain?". Finally, GIS offers powerful visualisation tools in the form of map and chart outputs that allow this information to be shared with a wider audience, including managers, policy makers, the media and the general public.