Geographic: Geography is the scientific study of the locational and spatial variation in both physical and biological phenomena on Earth. (The "where")
Information: A collection of facts or data. (The "what")
System: A group of interrelated parts working together (hardware, software, data, people...).
Formal definition of GIS: "A computer-based system to aid in the collection, maintenance, storage, analysis, output and distribution of spatial data and information (Bolstad, 2008)"
Spatial data is data with a "spatial component" describing where something is located on the Earth.
Aspatial data:
Elements of GIS
Collection: Internet, web services, GPS...
Maintenance: Quality control, metadata...
Storage: Files, folders, databases...
Analysis: Too many to list!
Output: Maps, tables, reports, pubs...
Distribution: Websites, web services...
Modeling the Real World
A world of physical entities that occupy space: (plants, trees, rivers, streets, etc.)
What: What are the physical features of interest and what are their properties and attributes?
Where: Where are these physical features located, both in terms of their absolute location (i.e., their coordinates) and their locations relative to other physical entities (their topology)?
When: When are certain conditions true and how do things change over time?
