The relationship between frequency and light/sound waves is that frequency determines the pitch or color of the wave.
In the case of sound waves, frequency refers to the number of oscillations or cycles per second and is measured in hertz (Hz). Higher frequencies correspond to higher-pitched sounds, while lower frequencies correspond to lower-pitched sounds. For example, a high-pitched whistle produces sound waves with a higher frequency than a low-pitched rumble.
In the case of light waves, frequency refers to the number of wave crests passing a given point in one second and is measured in terahertz (THz) or hertz (Hz). The frequency of light determines its color. Visible light, for instance, consists of a range of frequencies that our eyes perceive as different colors. Red light has a lower frequency, while blue light has a higher frequency.
In summary, frequency is a fundamental property of waves, and in the context of light and sound, it determines the pitch or color of the wave.