It is a type of motion in which energy is transferred from one region to another without the actual movement of the particles. During wave motion the transfer of energy and momentum from one point to another point of medium happens without actual transport of matter.

The distance between two consecutive crests or two consecutive troughs is called as the wavelength. It is inversely proportional to the frequency of the wave. The SI unit of wavelength is metre(m)

The number of oscillations or vibrations produced in one second is called as frequency. The frequency is inversely proportional to the time period of the wave. The SI unit of frequency is hertz.

The time taken for one complete oscillation or vibration is called as the time period. Time period is also defined as the time taken by a wave to travel a distance equal to its wavelength. The SI unit of time period is second.