This first content chapter of the book is meant to clarify the notions involved in the responsible management of information systems. The focus of this book is the concept of reflective responsibility, which will be developed in the subsequent chapters. However, the application of this theory will be the area of information systems. In order to develop what responsibility means in the context of information systems, we will therefore have to define the notion. This is not an easy task, as “information system” can mean many things. On the one hand there is the academic discipline, sometimes called information systems, computer information systems, management information systems, etc., and on the other hand there is the physical artefact. This artefact, be it a computer, a network, or some other type of ICT, becomes an information system by being used in social settings. Information systems have been defined as “an amalgam of hardware, software, procedures, and activities” (Lyytinen & Hirschheim, 1988, p. 19). This chapter will use another route to introduce the concept of information systems. It will look at three of the constitutive aspects of information systems, namely at business, information, and technology. By analysing these three terms and their composition, it will show what information systems are, and more importantly, why the theory of reflective responsibility is a promising approach to addressing the normative problems raised by them.