Photography, for its nature, covers different aspects: it is at the same time a document of reality, an object with its own technical characteristics, an expression of artistic vision and a tool for the historical documentation and cultural mediation towards other cultural assets. Through the ages, photography responded differently to those roles and with the advent of digital technologies its functions have been extended. This contribution examines these various aspects, starting from the photographic archives supporting the study of Art History, through the activity of cataloging and the photographic documentation of cultural heritage in Italy, up to art photography and virtual exhibitions. The conception and management of photography in the modern era, their merits and problems, is studied analysing its regulations and some good practices. Furthermore, the paper highlights the need of a wider awareness of the polysemy of photography, whose peculiar and complex nature can be effectively tackled just adopting a holistic, scientific approach.