radio or television summary of news events read by a newscaster or produced with a combination of reading and audio tape for radio or a combination of reading and film or video tape for television. It ranges from the one-minute dateline radio summary (usually a reading of five or six brief news items, each preceded by the city, state, or country in which it occurred) to the 15-minute newscast (usually divided into three groups: international, national, and local) to the 30-minute or one-hour newscast (generally longer items, integrating international, national, and local news and grouped according to related events) or even to an all-news format.

The newscast had a slow and difficult start in the U.S (United States). in the 1920s in the form of infrequent readings of headlines and front-page stories from the late editions of newspapers. That start eventually led to a series of battles, beginning in 1933, between the radio stations on the one hand and, on the other, the major American newspapers and the three news-service agencies that sustained them—the Associated Press, the United Press, and the International News Service. The most significant outgrowth of the conflict, after two years, was the formation by the networks of their own news-gathering organizations. Public interest in news increased significantly with the events that led to World War II, and the networks' news organizations gave the first proof of their potential during that period.

The television newscast began in 1953 as a televised version of the radio form, with elements adopted from the theatre newsreel. In fact, the staffs of television's newscasts were drawn largely from newsreel organizations. The increasing frequency and popularity of newscasts led to controversies by the end of the 1960s involving their objectivity. The Federal Communications Commission code (1941) governing broadcasters reads, “. . . the broadcaster cannot be an advocate,” and the code (1939) of the National Association of Broadcasters says, “Since the number of broadcasting channels is limited, news broadcasts shall not be editorial . . . .” Broadcasters were said by some to have violated these regulations, especially in newscasts.