What describes the number of times per second that an alternating current makes a complete cycle?

In electronics and radio, the term 'frequency' is used to describe how many complete cycles an alternating current (AC) or a radio wave completes in one single second. The standard unit of measurement for frequency is the Hertz (Hz), where one Hertz equals exactly one cycle per second. The other options measure entirely different properties. 'Wavelength' measures the physical distance a wave travels during one complete cycle, not the rate of the cycles. 'Speed' refers to how fast the wave propagates through a medium (like the speed of light), while 'pulse rate' is generally used for discrete bursts of energy rather than continuous alternating current.