This guide introduces readers to the essential concepts of an Energy Management System (EnMS), with a focus on the internationally recognized ISO 50001 standard. It explains why energy management is a strategic priority, the benefits of adopting an EnMS, and how ISO 50001 plays a pivotal role in reducing energy consumption while enhancing environmental sustainability. The book covers the essential aspects of ISO 50001, from its key definitions and principles to the PDCA (Plan-Do-Check-Act) cycle that underpins its effectiveness. It also provides practical insights on integrating ISO 50001 with ISO 14001, creating a comprehensive management system that aligns with both energy and environmental objectives. Readers will learn about the key differences between the 2011 and 2018 versions of ISO 50001 and how to successfully prepare for third-party assessments to achieve certification. Perfect for energy managers, sustainability professionals, and organizations aiming to improve their energy efficiency, this book offers a detailed roadmap for implementing ISO 50001 and achieving long-term energy savings. It also highlights the strategic advantages of integrating energy management with broader sustainability goals and environmental management practices.