The Power of a Set

If all you care about is iknow the fact that n is a prime number, that's fine. But now you want to study all the prime numbers as a setn ask no things about that. Or if want to move from just the natural numbers and you ask about o sign and cosignd and exponents and integrals... You suddenly find yourself dealing with sets. That's sort of where the true power counes to set theory from. The power set axiom.