centrepiece vs decoration

centrepiece and decoration both are nouns.

Word	Noun	Adjective	Verb	Adverb
centrepiece	Yes	No	No	No
decoration	Yes	No	No	No

As nouns, decoration is a hypernym of centrepiece; that is, decoration is a word with a broader meaning than centrepiece:

centrepiece: something placed at the center of something else (as on a table)
decoration: something used to beautify

Other hypernyms of centrepiece include ornament, ornamentation.

centrepiece (noun)	decoration (noun)
something placed at the center of something else (as on a table)	the act of decorating something (in the hope of making it more attractive)
the central or most important feature	something used to beautify
	an award for winning a championship or commemorating some other event