agreement vs consensus

agreement and consensus both are nouns.

Word	Noun	Adjective	Verb	Adverb
agreement	Yes	No	No	No
consensus	Yes	No	No	No

As nouns, consensus is a hyponym of agreement; that is, consensus is a word with a more specific, narrower meaning than agreement:

agreement: harmony of people's opinions or actions or characters
consensus: agreement in the judgment or opinion reached by a group as a whole

agreement (noun)	consensus (noun)
compatibility of observations	agreement in the judgment or opinion reached by a group as a whole
the thing arranged or agreed to
the verbal act of agreeing
the statement (oral or written) of an exchange of promises
the determination of grammatical inflection on the basis of word relations
harmony of people's opinions or actions or characters