In communications, such as radio and television, broadcasting means sending information such as television shows or music electronically to a large audience. The information is sent through the air in radio waves, through a wire, or by a communications satellite, and then the television viewers or radio listeners pick up the signal using their television sets and radio receivers. Gugliemo Marconi invented wireless telegraphy, in December 1901 he transmitted first radio signals across the Atlantic Ocean. This was point to point. Experiments with voice broadcasting began a few years later, and it grew rapidly in the 1920s.