The number of waves that pass through in a given second is called the frequency. The frequency of a wave is measured in hertz (Hz), which is equivalent to one wave per second. So, if a wave has a frequency of 1 Hz, it means that one wave passes through in one second. Similarly, if a wave has a frequency of 60 Hz, it means that 60 waves pass through in one second. The frequency of a wave is an important characteristic that determines how it is perceived by the human senses. For example, the frequency of sound waves determines how high or low a sound is perceived to be. Similarly, the frequency of light waves determines what color is perceived.