This book is positioned as a rst in a series of books on enterprise architecture needed for a Master of Enterprise Architecture program, and is targeted both at university students and practitioners with a drive to increase their understanding of these elds. As an introductory book, this book aims to explore the concept of enterprise architecture. At rst glance, writing such an introductory book might seem as a straight forward task of setting up a structure and lling in the blanks. However, writing this book turned out to be a pleasant journey of discovery. Based on our past experiences, each of us had a clear understanding of enterprise architecture, based on several years of experience and insight in the eld. However, when we started writing this book, and each of us exposed our individual understandings, it became apparent that our understanding of the eld differed in several ways. This prompted several discussions leading to an abundance of new insights. Without exception, thesediscussionstookplaceina pleasantandopenatmosphere,fueledbyourshared driveforunderstandingandincreasedinsight. Wearenowevenmoreconvincedthan before, that the eld enterprise architecture is a true multi-disciplinary profession. In the resulting book, we would like to share our insights, while also hoping to continue our discussions, now also involving you as a reader. We also realise that the journey is still far from complete. While this introductory book provides an overview of the eld of enterprise architecture from the perspective of our insights, many aspects need further re nement.