A radio tower

Radio is a way to send electromagnetic signals over a long distance, to deliver information from one place to another. A machine that sends radio waves is called a transmitter, while a machine that "picks up" the signals is called a receiver or antenna. A machine that does both jobs is a "transceiver". When radio signals are sent out to many receivers at the same time, it is called a broadcast.

Television also uses radio signals to send pictures and sound.