A wave is a disturbance in a medium or a field that carries energy without a net displacement of the particles that make up the medium.
The wave oscillates back and forth certain amount of times each time unit, that amount of times is called the frequency of the wave. On the other hand, the period of a wave is the time that it takes for the wave to oscillate back and forth one time. The period T and the frequency f are related through the formula:
The maximum displacement of the medium with respect to the equilibrium position is called the amplitude of the wave, and the distance where one complete oscillation can fit is called the wavelength of the wave.
The frequency f and the wavelength λ of a wave a related through the equation:
Where v is the speed of the wave.
Two kinds of waves are longitudinal and transverse waves.
In a longitudinal wave, the oscillations in the medium wave the same direction as the propagation of the wave. Two examples of longitudinal waves are a wave traveling along a spring and sound waves.
In a transverse wave, the oscillations in the medium are perpendicular to the direction in which the wave propagates. Two examples of transverse waves are a wave traveling through a string and electromagnetic radiation.