The book "Inorganic and Organic Photovoltaic Cells: A Comparative Study" offers a comprehensive analysis of the fundamental theories behind organic and inorganic solar cells. It highlights their applications, properties, and the essential differences between these two technologies. The discussion includes light absorption in inorganic materials, which leads to the generation of free electron-hole pairs, as well as the high efficiency values that can be achieved with mono- and multi-crystalline silicon. In contrast, organic photovoltaic cells (OPV) are addressed, which are based on molecular or polymeric organic compounds and utilize specific physical processes to generate photogenerated current. The book is aimed at professionals and students who wish to gain a deeper understanding of the functioning and challenges of both solar cell technologies.