GIS versus CAD versus DBMS: What Are the Differences?

Geographical Information System (GIS) is a hot topic. There is now a textbook and a journal devoted to the subject (Burrough, 1986; Coppock and Anderson, 1986) and it seems one can attend a conference on the subject practically any week. Although computer processing has been applied to geographical problems for more than a quarter of a century, it appears that there must be something different and more important about GIS that has caused so many diverse groups to take notice and invest so many resources. Yet there is much uncertainty about what the term GIS means. The purposes of this paper are to examine the alternative definitions of the dynamic field of GIS, and to attempt to distinguish GIS from other forms of automated digital analysis and mapping.