Explain the difference between a waves period and frequency

The time difference between the occurrences of two peaks is the period of the wave. The time difference between two consecutive black dots marked also gives the period of the wave. Generally, symbol ‘T’ is used to denote period in physics. Unit of measuring period is seconds (s).

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.