Broadcasting is the distribution of audio and/or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum (radio waves), in a one-to-many model.
The term “broadcasting,” derived from the method of sowing seeds in a field by casting them broadly about, originated in the early days of radio to distinguish radio broadcasting from methods using wired transmission (as in telegraph and telephone) or that were intended as person-to-person communication. Broadcasting is usually associated with radio and television, though in practice radio and television transmissions take place using both wires and radio waves.
The receiving parties may include the general public or a relatively small subset; the point is that anyone with the appropriate receiving technology can receive the signal. The field of broadcasting includes a wide range of practices, from relatively private exchanges such as amateur (ham) radio and amateur television (ATV) and closed-circuit TV, to more general uses such as public radio, community radio, and commercial radio, public television, and commercial television.
Transmission of radio and television programs from a radio or television station to home receivers over the spectrum is referred to as OTA (over the air) or terrestrial broadcasting and in most countries requires a broadcasting license. Transmissions using a combination of satellite and wired transmission, like cable television (which also retransmits OTA stations with their consent), are also considered broadcasts and do not require a license. Transmissions of television and radio via streaming digital technology have increasingly been referred to as broadcasting as well, though strictly speaking this is incorrect.