Broadcasting is the distribution of audio and video content to a dispersed audience via radio, television, or other. Receiving parties may include the general public or a relatively large subset of thereof. It could also be for purposes of private recreation, non‐commercial exchange of messages, experimentation, self‐training, and emergency communication such as amateur (ham) radio and amateur television (ATV). Economically there are a few ways in which stations are able to broadcast continually.
Each differs in the method by which stations are funded:
The first regular television broadcasts began in 1937. Broadcasts can be classified as "recorded" or "live". The former allows correcting errors, and removing superfluous or undesired material, rearranging it, applying slow‐motion and repetitions, and other techniques to enhance the program.
However, some live events like sports television can include some of the aspects including slow‐motion clips of important goals/hits, etc., in between the live television telecast. Many events are advertised as being live, although they are often "recorded live" (sometimes called "live‐to‐tape"). This is particularly true of performances of musical artists on radio when they visit for an in‐studio concert performance. Similar situations have occurred in television ("The Cosby Show is recorded in front of a live studio audience") and news broadcasting.
A broadcast may be distributed through several physical means. If coming directly from the studio at a single station or television station, it is simply sent through the studio/transmitter link to the transmitter and thence from the antenna on the tower out to the world.
Programming may also come through a communications satellite, played either live or recorded for later transmission. Networks of stations may simulcast the same programming at the same time, originally via microwave link, now usually by satellite. Distribution to stations or networks may also be through physical media, such as analog or digital videotape, compact disc (CD), DVD, and sometimes other formats. Usually these are included in another broadcast, such as when electronic news gathering (ENG) returns a story to the station for inclusion on a news program.
The final leg of broadcast distribution is how the signal gets to the listener or viewer. It may come over the air as with a radio station or television station to an antenna and receiver, or may come through cable television or cable radio (or "wireless cable") via the station or directly from a network. The Internet may also bring either internet radio or streaming media television to the recipient, especially with multicasting allowing the signal and bandwidth to be shared.
The term "broadcast network" is often used to distinguish networks that broadcast an over‐the‐air television signal that can be received using a television antenna from so‐called networks that are broadcast only via cable or satellite television. The term "broadcast television" can refer to the broadcast programming of such networks.