Definition
LFO doesn’t create sound or music. It can only modify a few parameters of sound. It can bend with a low frequency. Low-frequency oscillation (LFO) is clearly expressible a low level of sound generally below 20Hz. This LFO changes the sound produced by the original Oscillator. 
We use Hertz (Hz) to express Frequency . 1 Hz means one cycle per second. 100 Hz = 100 cycles-per-second. LFO can regulate the sound of oscillators at a slower rate. Generally, the slow rate is 10Hz or less. That means, the LFO varies 10 times per second or slower.
