Here's why:

* Frequency is defined as the number of wave cycles that pass a fixed point in one second.

* So, if you're asking about the frequency of a wave in one second, you're essentially asking for its frequency.

Example:

* If a wave has a frequency of 10 Hz (Hertz), it means 10 complete wave cycles pass a point in one second.

Let me know if you'd like to explore different wave characteristics or specific types of waves!