Television (TV), the system of mass communication, involving the transmission of images and sounds to distant screens, by electronic means over electrical or fiber-optic transmission lines or by electromagnetic radiation (radio waves). TV is a vastly important medium, for a number of reasons: the amount of time that many people spend watching it (31 hours per week, for average United States adults, 25 for Britons); its ability to bring together diverse groups of people in a sense of shared national identity; and its powerful role as a source of information about experiences other than the viewer’s own. It was the first medium to relay, via communications satellites, pictures across continents, and it is the prime route to the public for presenting news and current affairs, including the progress of wars and political campaigns. It is thus a powerful influence on public perception and opinion.

TV developed in Western Europe and North America but has spread across the world. In 1992 there were roughly 16 TV receivers for every 100 people. However, the distribution of TV is very uneven: there are around 80 sets per 100 US citizens, but only 2.3 per 100 people in non-Arab Africa. TV has in general been a very centralized form of communication, which does not easily permit access and participation. This is partly because TV transmission and production have been so expensive that only a few companies could become involved, and also because governments have strictly regulated who could gain access to the relatively scarce parts of the electromagnetic spectrum allocated for TV transmission. In the 1980s, many new forms of TV-related technology, such as cable television and Direct Broadcast Satellite, began to allow other forms of transmission and reception, and many governments began to relax their regulations about who could broadcast. These technological changes have helped bring about shifts in the cultural significance of TV. For more than 40 years, many of the most important national events, in a number of countries, have been experienced as TV events. Examples include the coronation of Queen Elizabeth II in 1953, the royal wedding of Prince Akihito in Japan in 1959, the annual Super Bowl football match in the United States, and the reporting of various international crises and political assassinations. However, some commentators have claimed that the era when TV served as a source of national bonding is coming to an end, as TV begins to appeal to smaller and more specific segments of the audience, rather than to entire societies. In spite of these changes, TV remains probably the most important form of mass communication of the late 20th century.