Here's an example. I know you haven't done trig, but the following will give you a sine wave if plotted for differennt values of x. I'm hoping that you know what a sine wave looks like, but you don't need to understand it.
y = a * sin(f*x)
where x is the variable.
a & f can be considered constants, where a is the amplitude and f the frequency. However, if we change the value of f, it will give us curves of different frequencies (i.e. different members in a 'family' of sine waves). Therefore, a & f are parametrics.
