Frequency is the number of wave/current/occurrences of a repeating event per unit of time at some fixed place. So if the event pass the place in 1/3 second, the frequency is 3 per second. Hertz is the SI unit of the frequency.
Formula: Frequency(f) = 1/Time Period(T) = f = 1/T.
In simple term, Frequency is inversely proportional to time.
