To boil = to cook something in boiling water, or, intransitively, for a liquid to reach the point where it starts to evaporate. I boiled the potatoes [in hot water]. The water is boiling. To spoil = transitively, to ruin something. Intransitively, to go off, to decay. He spoiled the party. The cheese is spoiling. Pronunciation-wise, there is no difference in the pronunciation of 'oil'.

'to spoil' has another different meaning. 'to spoil a child' for example is to weaken its character by complying unrestrainedly with its desires .

Yeah...So different, I supposed to learn how to use dictionary before ask! Sorry

These two words are so different, I am amazed you even ask. Perhaps you might want to learn how to use a dictionary.