What is a library? A piece of furniture, the place where that piece of furniture is placed, an institution, a publishing collection, a set of virtual texts? In each era, the typology of libraries has changed and, throughout history, the library as an institution has moved from the logic of storage, in which it was sought to preserve printed matter and other media, to the logic of flow, through the transfer of content to new media (digitization, for example), the creation of online content and the production of resources or metadata.

From classical antiquity to the libraries of the great Carolingian monasteries, then to the library of the kings of France, to the Vatican Library and to the Italian and German monumental collections, in this story Professor Frédéric Barbier brings into play perspectives of an intellectual, scientific, and above all political order: until the nineteenth century at least, The library has been a sign of distinction and, at the same time, a symbol of transcendence for those who held power. The history of libraries is directly linked to the history of thought, ideas, politics, information, and even architecture and urban planning. By adopting a broad chronological framework and emphasizing the comparative perspective, the author considers the topic in accordance with the transformations of the general media system from the past centuries to the present.