The term radio diffusion. Analog and digital broadcasting systems. The architecture of the broadcasting system: production of radio and television programs, exchange of radio and television program contents within the station and between publishers, content distribution to viewers and listeners via terrestrial, cable and satellite networks. Implementation of the system for reception on fixed, portable and mobile receivers. Realization of back channel and interactive services. Legislation related to the conduct of radio and television, concession grant, concession level: national, regional, local. Impact of the introduction of digital technology on the media market. A legal, technical-technological, program-content and business framework for accessing new publishers of radio and television in the electronic communications market. Digital dividend, introduction of new information and interactive services on a market basis.