"Is the water cold or hot?"

«Вода холодна чи гаряча?» is a question that would be answered «холодна» (if the water is cold) or «гаряча» (if the water is cold).

«Вода холодна або гаряча?» is a question that would be answered «так» (if the water is either hot or cold) or «ні» (if the water is lukewarm).

But not all speakers have this distinction, some people use those words interchangeably.