They are reciprocals of each other.
Period . . . . . . how long one of them takes.
Frequency . . . how often one of them happens.
This means that for the same wave or event,
(period) x (frequency) = 1 .
Examples:
Period . . . . . . 1 second
Frequency . . . 1 per second
Period . . . . . . 1/2 second
Frequency . . . 2 per second
Period . . . . . . 1 hour
Frequency . . . 24 per day
Period . . . . . . 1 minute
Frequency . . . 1/60 per second
Period . . . . . . 1 day
Frequency . . . 7 per week
Note:
In Physics, especially in electrical stuff, the most common
unit used for frequency is "per second"; so that unit is
given its own name: "Hertz", Hz .
