What does frequency measure in relation to waves?

Frequency measures the number of waves produced in one second. It is a fundamental concept in wave physics and is typically expressed in hertz (Hz), where one hertz equals one cycle per second. This definition highlights how frequency relates directly to the rate at which a repeating wave pattern occurs over time, allowing us to understand and quantify wave behavior effectively.

The other options represent different wave properties but do not define frequency. For instance, the speed of the wave relates to how fast the wave travels through a medium, which is distinct from the rate of wave cycles. The distance between two crests is a measurement of wavelength, indicating the length of one full wave cycle rather than how often waves occur. Lastly, the time taken for one complete wave is known as the period, which is the inverse of frequency. While all these concepts are interconnected, frequency specifically focuses on the number of cycles occurring each second.