This book provides a structured introduction to Reiki, outlining its core principles, historical background, and practical applications as a system of energy awareness and mindfulness-based practice. It explains how Reiki approaches physical, emotional, and mental balance through concepts such as universal energy, hand positions, meditation, and intentional focus, while clearly distinguishing Reiki as a complementary practice rather than a replacement for conventional medical care. The content explores foundational topics including Reiki philosophy, ethical principles, symbols, and the traditional stages of learning. The book is intended for beginners with little or no prior experience in Reiki, as well as readers interested in holistic practices, mindfulness, and personal energy awareness. It is suitable for adults of all ages who want an organized overview of Reiki concepts, including those curious about self-care practices, relaxation methods, and non-invasive approaches to well-being for themselves, others, and animals. The approach is primarily educational and practical, combining descriptive explanations with step-by-step guidance, exercises, and illustrative examples. Readers are introduced to self-practice techniques, basic session structures, symbol usage, chakra awareness, and the integration of elements and crystals, offering a comprehensive reference-style introduction designed for both study and personal exploration.