The invention and application of reproduction technologies lead to the evolution of mass media as a distinct system of social functions. As a social configuration characterized by distributed communication, the operation of mass media is closed. In its differentiation from the environment, mass media use information/non-information as its operant code, treat three categories as strategy, and adopt self-reference and other-reference as modes of operation to build its own reality. The reality of mass media has dual significance: it doubles as the ongoing observable operations of mass media, and as the society and reality resultant from its operations. The mass media function to facilitate the self-observation of various systems of the whole society. Thereby, it continuously provides background knowledge to other social systems to form the basis and source of knowledge in everyday life. Its production has to be accepted as real despite haunting suspicion on manipulation. Varying profoundly from extant mass media and journalism studies, Luhmann’s insights subvert many of the latter’s accepted premises, and offer new perspectives and thoughts on communication research.