A historical-critical journey through the many transformations that the idea of photography and its practice, at times coinciding with true movements, have undergone from their nineteenth-century origins to the current digital shift. Each chapter does not linger on descriptions and lists of names or data, but critically analyzes a historical moment in which a prevailing concept of photography takes shape through the work of the most relevant authors, in connection with the social and cultural developments that characterize that moment. Every chapter is completed by a brief anthology of writings by photographers, experts in the discipline or intellectuals who have addressed it. Throughout the discussion, strong attention is paid to photography as an art form in the making.