An information system consists of a collection of entities and their relationships. Information systems act to collect, store, process, and transport information. This chapter argues that there are two polar types of information systems. The first, the organizational process information system (OPIS), relies upon the organizational structures as its information system. The second, the technologically augmenting information system (TAIS), supplements the OPIS. A TAIS relies on a combination of technology and its users to augment human communication. Every OPIS has had its supporting TAISs ever since the invention of writing. In the past century the capacity improvements in TAISs created by improved communications, improved information processing capabilities, and developments in understanding of decision theory and management science models have created miracles and headaches for those operating organizations.