The difference between Agreement and Concord

Agreement as a noun (countable):

An understanding between entities to follow a specific course of conduct.

Agreement as a noun (uncountable):

A state whereby several parties share a view or opinion; the state of not contradicting one another.

Agreement as a noun (uncountable, legal):

A legally binding contract enforceable in a court of law.

Agreement as a noun (uncountable, linguistics, grammar):

Rules that exist in many languages that force some parts of a sentence to be used or inflected differently depending on certain attributes of other parts.

Agreement as a noun (obsolete, chiefly, _, in the plural):

An agreeable quality.

Concord as a noun:

A state of agreement; harmony; union.

Concord as a noun (obsolete):

Agreement by stipulation; compact; covenant; treaty or league

Concord as a noun (grammar):

Agreement of words with one another, in gender, number, person or case.

Concord as a noun (legal, obsolete):

An agreement between the parties to a fine of land in reference to the manner in which it should pass, being an acknowledgment that the land in question belonged to the complainant. See fine.

Concord as a noun (probably influenced by [[chord]], music):

An agreeable combination of tones simultaneously heard; a consonant chord; consonance; harmony.

Concord as a noun:

A variety of sweet American grape, with large dark blue (almost black) grapes in compact clusters; a Concord grape.

Concord as a verb (intransitive):

To agree; to act together