In this category the most important formulas are listed which describe the characteristics of waves. In physics, waves are present in various phenomena. In fluids like water, mechanical waves easily can be seen, but also sound propagates in the form of a wave. Furthermore, electromagnetic waves are of big importance. On the one hand from the technological point of view radiowaves are used to transmit information. On the other hand electromagnetic waves are present in nature as light or radiation. The characteristic parameters which describes the form of a wave are the amplitude, the frequency which can also be expressed by the wavelength or the wavenumber and the velocity of propagation.