Wavelength is the distance between two successive points whch are in phase, that is the points are doing the same thing at the same time. Wavelength, l, is measured in metres (m).

Wavespeed is the distance the wave travels through the medium each second.
Wavespeed, v, is measured in metres per second (m s¯¹).

The period of a wave is the time needed for each particle to complete one full wave movement.
Period, T, is measured in seconds (s).

The frequency of a wave is the number of waves passing a given point in the medium each second.
Frequency, f, is measured in hertz (Hz).

Frequency is the reciprocal of period, and period the reciprocal of frequency, that is:

The amplitude of a wave is the maximum displacement of particles from their rest position, or in the case of a pressure wave, amplitude is the maximum change of pressure from normal air pressure. Waves with bigger amplitude carry more energy.