Molecular photochemistry has garnered significant interest of researchers and scholars across the globe. This book has been compiled with the intention of addressing utilization of basic fundamentals and principles to more complex concepts in various fields of photochemistry. It is unique in its approach in comparison to various classical books on photochemistry which provide detailed accounts limited only to the basics of molecular photochemistry. There has been an overview on the core concepts used in diverse spheres of photochemistry which are not easily accessible. The aim of this text is to update academicians, students and experts actively involved in the field of molecular photochemistry. Latest developments have been highlighted and different functions of the technology in solution, metal oxides, biology, computational aspects and other applications have been dealt with. This book presents a unique overview on photochemistry.