Forms of electronic broadcasting

Historically, there have been several different types of electronic broadcasting mediums:

• Telephone broadcasting (1881–1932): the earliest form of electronic broadcasting (not counting data services offered by stock telegraph companies from 1867, if ticker-tapes are excluded from the definition). Telephone broadcasting began with the advent of Théâtrophone ("Theatre Phone") systems, which were telephone-based distribution systems allowing subscribers to listen to live opera and theatre performances over telephone lines, created by French inventor Clément Ader in 1881. Telephone broadcasting also grew to include telephone newspaper services for news and entertainment programming which were introduced in the 1890s, primarily located in large European cities. These telephone-based subscription services were the first examples of electrical/electronic broadcasting and offered a wide variety of programming .
• Radio broadcasting (experimentally from 1906, commercially from 1920): radio broadcasting is an audio (sound) broadcasting service, broadcast through the air as radio waves from a transmitter to an antenna and, thus, to a receiving device. Stations can be linked in radio networks to broadcast common programming, either in syndication or simulcast or both.
• Television broadcasting (experimentally from 1925, commercially from the 1930s): this video-programming medium was long-awaited by the general public and rapidly rose to compete with its older radio-broadcasting sibling.
• Cable radio (also called "cable FM", from 1928) and cable television (from 1932): both via coaxial cable, serving principally as transmission mediums for programming produced at either radio or television stations, with limited production of cable-dedicated programming.
• Satellite television (from circa 1974) and satellite radio (from circa 1990): meant for direct-to-home broadcast programming (as opposed to studio network uplinks and downlinks), provides a mix of traditional radio and/or television broadcast programming with satellite-dedicated programming.
• Webcasting of video/television (from circa 1993) and audio/radio (from circa 1994) streams: offers a mix of traditional radio and television station broadcast programming with internet-dedicated webcast programming.

Economic models

Economically there are a few ways in which stations are able to broadcast continually. Each differs in the method by which stations are funded:

• in-kind donations of time and skills by volunteers (common with community broadcasters)
• direct government payments or operation of public broadcasters
• indirect government payments, such as radio and television licenses
• grants from foundations or business entities
• selling advertising or sponsorships
• public subscription or membership

Broadcasters may rely on a combination of these business models. For example, National Public Radio, a non-commercial network within the U.S., receives grants from the Corporation for Public Broadcasting (which, in turn, receives funding from the U.S. government), by public membership and by selling "extended credits" to corporations.