The intent of Natural Family Planning is to use the natural rises and falls in fertility to regulate or achieve pregnancy.
As I said, it is a distinction without a difference.
There is a difference. NFP does nothing to your fertility. It does not break your body, it does not cause it to cease to function as it was created to. NFP does not separate life from love. There is nothing different between the act that produces a child and one that doesn't. The couple has not choosen to, by their own actions, to destroy their capability to love with life giving love, and so mirror the Creator.
So the intent is the same as contraception which impedes fertilization without being abortiofacient.