agreement vs harmony

agreement and harmony both are nouns.

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

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

As nouns, harmony is a hypernym of agreement; that is, harmony is a word with a broader meaning than agreement:

agreement: harmony of people's opinions or actions or characters
harmony: a harmonious state of things in general and of their properties (as of colors and sounds); congruity of parts with one another and with the whole

Other hypernyms of agreement include concord, concordance.

agreement (noun)	harmony (noun)
compatibility of observations	an agreeable sound property
the thing arranged or agreed to	compatibility in opinion and action
the verbal act of agreeing	agreement of opinions
the statement (oral or written) of an exchange of promises	the structure of music with respect to the composition and progression of chords
the determination of grammatical inflection on the basis of word relations	a harmonious state of things in general and of their properties (as of colors and sounds); congruity of parts with one another and with the whole
harmony of people's opinions or actions or characters