Amplitude modulation (AM) is a modulation technique. It is utilized for sending messages with a radio carrier wave. The signal strength of the carrier wave is varied with that of the message signal, for example, an audio signal. There are three kinds of amplitude modulation: Double sideband-suppressed carrier modulation (DSB-SC), Single Sideband Modulation (SSB), and Vestigial Sideband Modulation (VSB).