Thunder and lightning occur simultaneously. It is known that the speed of light in air is [\(3\times10^8m/s\)], while the speed of sound in air is [\(330\ m/s\)].
Because the speed of light is significantly greater than the speed of sound, the flash is observed well before the sound of thunder during a lightning event.
Sound is a vibration that propagates the mechanical wave of displacement and pressure, through a medium can be of any matter. In other words, the sound is the thin line between Music sound and Noise.
Sound can be divided into two types depending on its frequency. The following are:-