playoff vs competition

playoff and competition both are nouns.

Word	Noun	Adjective	Verb	Adverb
playoff	Yes	No	No	No
competition	Yes	No	No	No

As nouns, competition is a hypernym of playoff; that is, competition is a word with a broader meaning than playoff:

playoff: any final competition to determine a championship
competition: an occasion on which a winner is selected from among two or more contestants

Other hypernyms of playoff include contest.

playoff (noun)	competition (noun)
any final competition to determine a championship	the act of competing as for profit or a prize
	an occasion on which a winner is selected from among two or more contestants
	the contestant you hope to defeat
	a business relation in which two parties compete to gain customers