This book delves into the evolving landscape of microgrids, offering a comprehensive guide on their design, operation, and integration within modern electrical networks. The subject of this book is microgrids, which are pivotal in the transition toward decentralised, decarbonised, and digitalised energy systems. The book is structured around several practical use cases, detailing the methods and results that will be of particular interest to readers, such as optimisation of power flow, integration of distributed energy resources (DERs), and advanced energy management systems. It features an array of illustrations, tables, and diagrams that enhance the reader's understanding of complex concepts, along with a didactic approach that includes step-by-step guides and case studies of 30 microgrid projects from around the world.  Readers will benefit from detailed insights into the economic, technical, and social aspects of microgrids, including their role in enhancing grid resilience, improving energy efficiency, and supporting renewable integration. The book also addresses the latest technological advancements, such as digital twins and machine learning applications, that are shaping the future of microgrid design and operation. It serves as a practical manual, providing frameworks and methodologies that can be applied in real-world scenarios to optimise microgrid performance. The unique combination of theoretical knowledge and practical experience makes this book a valuable resource for researchers, engineers, policymakers, and practitioners in the energy sector.