The frequency,
f, of
the wave,
is the total number of complete waves that pass
a fixed point in one second. Wave frequency is
measured in hertz (Hz). 

The period,
T,
of a wave,
is the length of time it takes one complete wave
to pass a point  this is measured in seconds.
The frequency, f, and period, T, are related
by the equation:
f = 1/T. 

The speed,
s, of
a wave,
is a measure of how fast a complete wave travels
from one point to another. It is given in metres
per second (m/s). 