Graphing Trig functions

I know that when you graph trig functions, you need the period and the amplitude. My teacher keeps asking the class how many cycles are there... what does she mean by the cycles? She gave the definition (one cycle is equal to the length of the period; one revolution around the unit circle) but I still don't get it

for example:

y=2cos3x

A= 2
P= 2pi/3

what is the cycle for this?

one cycle is equal to the length of the period => 1 period = one cycle.

y=2cos3x

A= 2
P= 2pi/3

what is the cycle for this? => 2pi/3

note: a cycle mean from a point to another exactly same situation point.
like from 0 upward to next 0 upward.