The third edition of Preserving Digital Materials provides a survey of the digital preservation landscape. This book is structured around four questions: 1. Why do we preserve digital materials? 2. What digital materials do we preserve? 3. How do we preserve digital materials? 4. How do we manage digital preservation? This is a concise handbook and reference for a wide range of stakeholders who need to understand how preservation works in the digital world. It notes the increasing importance of the role of new stakeholders and the general public in digital preservation. It can be used as both a textbook for teaching digital preservation and as a guide for the many stakeholders who engage in digital preservation. Its synthesis of current information, research, and perspectives about digital preservation from a wide range of sources across many areas of practice makes it of interest to all who are concerned with digital preservation. It will be of use to preservation administrators and managers, who want a professional reference text, information professionals, who wish to reflect on the issues that digital preservation raises in their professional practice, and students in the field of digital preservation.