paradox vs contradiction

paradox and contradiction both are nouns.

Word	Noun	Adjective	Verb	Adverb
paradox	Yes	No	No	No
contradiction	Yes	No	No	No

As nouns, contradiction is a hypernym of paradox; that is, contradiction is a word with a broader meaning than paradox:

Other hypernyms of paradox include contradiction in terms.

paradox (noun)	contradiction (noun)
(logic) a statement that contradicts itself	the speech act of contradicting someone
	(logic) a statement that is necessarily false
	opposition between two conflicting forces or ideas