Communion vs Holy Communion

Communion and Holy Communion both are nouns.

Word	Noun	Adjective	Verb	Adverb
Communion	Yes	No	No	No
Holy Communion	Yes	No	No	No

As nouns, Communion and Holy Communion are synonyms defined as:

Communion and Holy Communion: the act of participating in the celebration of the Eucharist

Other synonyms of Communion include manduction, sacramental manduction.

Communion (noun)	Holy Communion (noun)
the act of participating in the celebration of the Eucharist	the act of participating in the celebration of the Eucharist