Wavelength refers to the distance between two successive crests and troughs of sea waves. It is measured in the direction of the wave. Crest is the highest point of the wave whereas the trough is the lowest. The wave height of a surface wave is the difference between the elevations ofa crest and a neighbouring trough. A wave frequency is the number of waves that pass a fixed point and the number of cycles or vibrations undergone during one unit of time by a body in periodic motion. Wavelength is inversely related to frequency which refers to the number of wave cycles per second. The higher the frequency of the signal, the shorter the wavelength.