All sounds are caused by vibrations. The frequency of a sound wave is the number of times the sound source vibrates per second. The higher the frequency of a sound wave, the higher the pitch of the sound.
Frequency can also be used to measure the rate at which other events occur, such as the rate at which a light bulb blinks or the rate at which a car engine fires its cylinders.
In physics, frequency is related to wavelength by the following equation:
```
f = c / λ
```
where:
* f is frequency in cycles per second (Hertz)
* c is the speed of the wave in meters per second
* λ is the wavelength of the wave in meters
The frequency of a wave is inversely proportional to its wavelength. This means that waves with shorter wavelengths have higher frequencies, and waves with longer wavelengths have lower frequencies.
