The book "Light and Light Sources" provides a comprehensive introduction to the operating principles of high-intensity discharge lamps (HID). It highlights the challenges and issues associated with the development and operation of these lamps. Additionally, modern methods for electrode and plasma diagnostics, as well as numerical techniques for analyzing HID lamps, are discussed. This specialized book is aimed at both students and scientists and researchers in universities and industry who seek a deeper understanding of the technology and application of light sources.