A stream, feed or recording, usually containing audio and/or images, which is produced once and then released to the public, sometimes live, in realtime. There is a lot of information which is broadcast under a proprietary license. Broadcasts are generally free with advertisements but some are pay-per-view.
Radio and television networks have been routinely broadcast over the airwaves for three quaters of a century. Large scale public broadcasts can involve high voltage transmission hardware and regulations to coordinate licenses, codes of conduct and conditions.