Broadcasting is the distribution of audio and/or video signals which transmit programs to an audience. The audience may be the general public or a relatively large sub-audience, such as children or young adults.
Transmission of sound or images by radio or television.
Transmission of sound or images to a large number of receivers by radio or television.
Thus, an Internet channel may distribute text or music worldwide, while a public address system in a workplace may broadcast very limited ad hoc "soundbites" to a small population within its range. Broadcasting may involve auditory information only, as in radio, or visual, or a combination, as in television. As technology has advanced, so too have the forms of broadcasting. Historically, the term broadcasting usually has referred to the radio and television industries. Broadcasting was previously synonymous with "over the air" broadcasts, where the radio frequency spectrum is limited and thus regulated; but with the advent of direct (satellite) radio broadcasting and especially cable television, channels (and programming variety) are far more numerous (digital cable television can support hundreds of different channels) and are subscriber-based. The concept and ability of broadcasting to convey the same information, whether announcements of current events, educational material or simply entertainment, to a worldwide audience simultaneously, is a great advance in allowing humankind to overcome long-standing barriers.