Public broadcasting involves radio, television and other electronic media outlets whose primary mission is public service. In many countries of the world, funding comes from governments, especially via annual fees charged on receivers.
Public broadcasting may be nationally or locally operated, depending on the country and the station. In some countries a single organization runs public broadcasting. Other countries have multiple public-broadcasting organizations operating regionally or in different languages. Historically, public broadcasting was once the dominant or only form of broadcasting in many countries (with the notable exceptions of the United States, Mexico and Brazil). Commercial broadcasting now also exists in most of these countries; the number of countries with only public broadcasting declined substantially during the latter part of the 20th century.