This book provides a comprehensive course in optics that brings together the fundamentals of geometric and wave optics, as well as application examples and descriptions of many optical devices and instruments. The set of concepts covered ranges from the entire field of geometric and wave optics and an interesting introduction to quantum optics and offers a clear vision of optics. The book's diagrams allow a visual and concrete illustration of optical phenomena in relation to the text. Detailed technical explanations are given, with a physical approach and precise mathematical formalism. It is particularly intended for first year students (MPSI, PCSI, PTSI) and second year students (MP-MP, PC-PC and PSI-PSI) and for undergraduate and graduate students. It will also be of interest to engineers and researchers seeking basic training in optics.