This book gives a condensed introduction to information systems and their use in companies and organisations. Their role in organisations and how they can contribute to a successful enterprise is explained. The book has a non-technical focus, but introduces fundamental technical concepts and vocabulary, such as computer parts, data storage, databases and networks. The fundamentals of systems development are explained. Attention is also given to ­ethical aspects of information systems and their role in society.Essentials of Information Systems introduces the concept of ­information systems in a condensed and accessible form. The book equips the reader with basic knowledge of the information systems necessary in any modern organisation.This book can be read by anyone interested in information ­systems. It is particularly suitable for introductory courses in ­business and information systems. The second edition is updated with extended information on topics such as Blockchain, Big data, A/I and Internet of Things. The discussion on privacy, ethics, source evaluation and environmental aspects of IT has been expanded. Further, more study questions and examples have been added.