What is the difference between GIS and CAD?
Both GIS and CAD work primarily with graphical vector data (they also use image data which is a collection of unrelated pixels). However CAD (Computer Aided Design) does not deal with projected data and is not built on a relational database foundation as GIS is. Common database operations such as queries and statistical analyses are augmented in GIS with queries and spatial operations on the geographic data types themselves giving the GIS analyst an extremely powerful set of tools.