This document introduces GIS (geographic information systems) and its applications in archaeology. It defines GIS as a system that deals with locations and distributions of people, places, and things using databases of information. The document outlines early uses of GIS in archaeology projects in the 1990s and discusses how GIS has been applied to cultural resource management, landscape analysis, and visualization of sites over time. Potential issues with GIS applications include biases introduced by original data and an inability to fully represent temporal or experiential aspects of landscapes.