ABSTRACT
This chapter formally presents Geographic Information Systems (GIS). The chapter starts with a discussion of what a GIS is and what it can and cannot do. In this discussion, specific GIS software product references are avoided as much as a possible to ensure you understand the underlying principles of GIS that are used in specific GIS technologies. The chapter then discusses the most important and time-consuming aspect of working with a GIS-GIS data. You will learn about conceptual differences in how the earth is digitally referenced and represented in various GIS data model formats. Additionally, you will learn about GIS metadata-a critical item to ensure that the GIS data you select is relevant to your GIS operational needs. The second half of the chapter is devoted to specific GIS technology. In this part of the chapter, you will learn about commercial, open-source, and open/web-based GIS software. This part of the book is the one that is most likely to change quickly as specific GIS technology is constantly and rapidly changing, and you will need to keep track of these changes. However, the foundational
concepts learned in the beginning of this chapter should serve to keep your skill and knowledge set relevant even as specific GIS software products change. The first section presents an overview of GIS.
