There are many different views on what the term Information Systems means. This paper provides a simple explanation of what an Information System is in practice to assist in clarifying the confusion. If this simple explanation were widely understood, then current difficulties with Information Systems development, practical problems with ongoing Information Systems, the applicability of much Information System’s research, and a general lack of awareness of the potential for the academic study of Information Systems, could all be improved upon. The description of what a practical Information System turns out to be is given, and the reasons why its major features exist and are important are discussed. Implications arising from the acceptance of this definition are offered.