Energy on the skin has revolutionized medicine: in the last 25 years laser and IPL devices have made completely new medical treatment concepts possible, with considerable therapeutic success. The rapid technical advances in energy-based instruments require continuous training for attending physicians. This book presents all the available energy-based systems for the treatment of cutaneous diseases, including a wide range of laser applications, IPL and energy-based devices such as the lightning lamp-pumped pulsed dye laser, solid state lasers like neodymium-doped yttrium aluminum garnet (Nd YAG) laser, quality switched ruby laser, erbium-doped yttrium aluminum garnet laser (YAG) and CO2 laser, as well as radio frequency and high-intensity focused ultra sound, photodynamic therapy and more. The translation was done with the help of artificial intelligence (machine translation by the service DeepL.com) and a subsequent human revision by original chapter authors, editor and publisher was perfomed to fine-tune and update the content. After discussing the history of the laser, the first part of the book focuses on laser therapy in dermatology and aesthetic medicine, including side effects, complications and treatment errors. It also examines the qualitative standards and legal aspects, from therapists’ qualifications to patient education and the maintenance of the equipment. In addition, it addresses safe and effective energy applications for hemangiomas, skin cancer precursors and rosacea. The book also features chapters on patient preparation, medical history and photographic follow up, as well as skin analysis, cooling techniques, light protection and the maintenance of laser devices. Further, it discusses cosmetic topics such as tattoo removal, photo hair removal, scars and stretch marks, hair transplant, body contouring, hyperhidrosis, and aesthetic plasma medicine. Written by leading international exerts, each contribution includes suggestions for further reading, making the book a valuable resource for beginners and experts alike. At the same time, its easy-to-follow, didactic style means that it is also suitable for university courses and seminars.