commemoration vs ceremony

commemoration and ceremony both are nouns.

Word	Noun	Adjective	Verb	Adverb
commemoration	Yes	No	No	No
ceremony	Yes	No	No	No

As nouns, ceremony is a hypernym of commemoration; that is, ceremony is a word with a broader meaning than commemoration:

Other hypernyms of commemoration include ceremonial, ceremonial occasion, observance.

commemoration (noun)	ceremony (noun)
a recognition of meritorious service	the proper or conventional behavior on some solemn occasion
a ceremony to honor the memory of someone or something	any activity that is performed in an especially solemn elaborate or formal way
	a formal event performed on a special occasion