What is the Full Form of FM ?

FM - Frequency Modulation

In Telecommunication, Frequency Modulation is a technique of transmitting information using a carrier wave. The frequency of the carrier wave is varied in accordance with the amplitude and polarity of the input signal.

It is different from Amplitude Modulation (AM) in which an Amplitude of the signal is modified. However, FM signals do not travel as far as AM. The FM broadcasting technology was pioneered by Edwin Howard Armstrong.

FM Radio
In general, FM radio refers to radio that is broadcasted using frequency modulation. Frequency modulation is widely used for a variety of radio communications applications. The main advantage of using FM radio instead of AM is its audio quality and immunity to noise. The frequency band for FM radio is about 88 to 108 MHz. FM radio maybe appropriately referred to as "high-fidelity".