Here's why:

* Frequency refers to how many times a sound wave vibrates per second. It's measured in Hertz (Hz).

* Pitch is our perception of how high or low a sound is.

* Higher frequency means more vibrations per second, resulting in a higher pitch.

* Lower frequency means fewer vibrations per second, resulting in a lower pitch.

For example, a high-pitched whistle has a high frequency, while a deep bass note has a low frequency.