confession vs declaration

confession and declaration both are nouns.

Word	Noun	Adjective	Verb	Adverb
confession	Yes	No	No	No
declaration	Yes	No	No	No

As nouns, declaration is a hypernym of confession; that is, declaration is a word with a broader meaning than confession:

confession (noun)	declaration (noun)
(Roman Catholic Church) the act of a penitent disclosing his sinfulness before a priest in the sacrament of penance in the hope of absolution	a statement that is emphatic and explicit (spoken or written)
an admission of misdeeds or faults	a formal expression by a meeting; agreed to by a vote
a written document acknowledging an offense and signed by the guilty party	(law) unsworn statement that can be admitted in evidence in a legal transaction
a public declaration of your faith	a formal public statement
the document that spells out the belief system of a given church (especially the Reformation churches of the 16th century)	(contract bridge) the highest bid becomes the contract setting the number of tricks that the bidder must make
	a statement of taxable goods or of dutiable properties