A GIS creates maps from data pulled from databases. Existing paper maps can be digitized and translated into the GIS as well. The GIS-based cartographic database can be both continuous and scale free. Map products can then be created centered on any location, at any scale, and showing selected information symbolized effectively to highlight specific characteristics. A map can be created anytime to any scale for anyone, as long as you have the data.
Pattern recognition is something human beings excel at.
There is a vast difference between seeing data in a table of rows and columns and seeing it presented in the form of a map. GIS gives you the layout and drawing tools that help present facts with clear, compelling documents.