Information systems are used for the collection and storage of information. Some examples of information systems are enterprise resource planning, data warehouses, geographic information system, global information system, etc. This book presents the complex subject of information systems in the most comprehensible and easy to understand language. As this field is emerging at a rapid pace, the contents of this book will help the readers understand the modern concepts and applications of the subject. Students, researchers, experts and all associated with information systems will benefit alike from this book.