Both words can be used in different situations, but there is one case when their meaning is quite similar, e.g.:
Мама: помой полы, пожалуйста!
Сын: хорошо, помою.
Сын: ладно, помою.
I believe, there is small emotional difference here. "Ладно" is more about doing a favor, while "хорошо" is just a confirmation, like "yes, I will do it, no problem". But it could be my personal perception. Others please correct me!