The Doppler Effect is a phenomenon observed when there is a change in frequency or wavelength of a wave in relation to an observer moving relative to the source of the wave. This effect is often demonstrated in the context of sound waves, such as the change in pitch of a passing ambulance siren. The Doppler Effect can be explained using the formula: f' = f (v ± vo) / (v ± vs), where f' is the observed frequency, f is the actual frequency of the wave, v is the speed of the wave in the medium, vo is the speed of the observer, and vs is the speed of the source. When the observer moves towards the source, the frequency of the wave appears higher, resulting in a higher pitch. Conversely, when the observer moves away from the source, the frequency appears lower, resulting in a lower pitch. The Doppler Effect is not only applicable to sound waves, but also to light waves and other types of waves. It has many practical applications, such as in radar technology, astronomy, and medical imaging. Understanding the Doppler Effect is crucial in various fields of science and engineering, as it allows us to better comprehend the behavior of waves and their interactions with moving objects.