"The dollars are in the bank."
Translation:Los dólares están en el banco.
Están indicates a temporary state, while son means something that lasts, for instance if you wanted to say "my car is dirty" you're gonna use estar, because your car is only temporarily dirty, after some kind of off-road fun you had. Now if you wanted to say "my car is fast" then you'd use ser (infinitive form for son), because your car isn't fast only at the moment of speaking, it's fast in general, if you take it for a spin next week it's still gonna be fast. Hope that helped