marriage vs marriage ceremony

marriage and marriage ceremony both are nouns.

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

As nouns, marriage and marriage ceremony are synonyms defined as:

marriage and marriage ceremony: the act of marrying; the nuptial ceremony

Other synonyms of marriage include wedding.

marriage (noun)	marriage ceremony (noun)
the act of marrying; the nuptial ceremony	the act of marrying; the nuptial ceremony
two people who are married to each other
the state of being a married couple voluntarily joined for life (or until divorce)
a close and intimate union