Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum, in a one-to-many model. Broadcasting began with AM radio, which came into popular use around 1920 with the spread of vacuum tube radio transmitters and receivers. Before this, most implementations of electronic communication were one-to-one, with the message intended for a single recipient. The term broadcasting evolved from its use as the agricultural method of sowing seeds in a field by casting them broadly about. It was later adopted for describing the widespread distribution of information by printed materials or by telegraph. Examples applying it to "one-to-many" radio transmissions of an individual station to multiple listeners appeared as early as 1898.

श्रब्य और/अथवा विडियो संकेतों को एक स्थान से सभी दिशाओं में, या किसी एक दिशा में फैलाना प्रसारण (broadcasting) कहलाता है। दूरस्थ स्थानों पर इन संकेतों को उपयुक्त विधि से ग्रहण किया जाता है एवं आवश्यक परिवर्तनों के बाद कोई श्रब्य या विडियो आदि प्राप्त होता है।