The book "Biophotons" offers a comprehensive examination of the biophotons emitted by living systems. It explains that all living organisms exhibit a weak but constant emission of photons in the visible and ultraviolet range. This biophoton emission is associated with numerous biological and physiological functions. The book highlights the possibility of a previously overlooked information channel within living systems and discusses how biophotons can influence chemical reactivity in cells, growth regulation, differentiation, and intercellular communication. The authors, leading international scientists in this field, present both the experimental and theoretical foundations, shedding light on technical challenges as well as the diverse applications in various areas such as the food industry, medicine, pharmacology, and environmental sciences. The extensive literature on this topic is also addressed.