This book will be an essential read for all new teachers or trainers in medicine and the healthcare professions, while encouraging the more experienced teacher to review their educational responsibilities. It looks at teaching from the perspective of the functions or roles of a teacher. While aiming to maintain both brevity and clarity it adopts a personal style and approach in order to provide a flavour of what it means to be a teacher. The authors describe the eight key roles for the teacher or trainer. For maximum effectiveness and job satisfaction it is important for every teacher to establish their roles in an education programme and to know how to contribute most effectively. This book is written to assist with these goals. All teachers should have an understanding of the eight roles but cannot be expected to be an expert in all of them. A consideration of these roles illuminates what is expected of a teacher and illustrates how to maximise potential. All the chapters contain brief overviews, key take-home messages, a summary of the role responsibilities of all teachers, 'expert' teachers and 'master' teachers, and suggestions for consideration by the teacher as to their personal role. At the end of each chapter is a list of references of the topics addressed in the chapter. The text includes short narratives from 38 teachers around the world as well as personal anecdotes to provide an additional insight into the roles a teacher fulfils. The first chapter highlights the importance of the teacher in an educational programme and how the teacher is critical to the success of the learner. The second chapter provides an overview of the eight roles and how they are interconnected. The subsequent chapters describe in turn each of the roles, highlighting what is expected of a teacher, what is required of an expert teacher, and what is anticipated of a master teacher who is an innovator in the field relating to a particular role. The final chapter reviews the eight roles in the context of the day-to-day work of the teacher and how these roles are changing.