Probabilistic curves study, how to?

Hi everybody!

I am working with severals probability curves and I would like to compare variability between them. Further, I would like to compare variability of each probabilistic curve by using some statistics results. Then, I have some questions:

1) How to calculate standard deviation of diferents curves? For example, standard deviation of a normal curve is calculated as the same as standard deviation of Poisson or Binomial?

2) How do I compare variability between them? I would like to analyze the variability between different data gathered, which it is fitted by different probabilistic curves. Then, which method is adviced to compare variability?

Thank you guys!

João Campos