@Butrflynet,
Irony: the expression of one's meaning by using language that normally signifies the opposite, typically for humorous or emphatic effect
Paradox: a statement or proposition that, despite sound (or apparently sound) reasoning from acceptable premises, leads to a conclusion that seems senseless, logically unacceptable, or self-contradictory
Oxymoron: a figure of speech in which apparently contradictory terms appear in conjunction
I understand oxymorons the most, but I am still confused about how the usage differs!