Treaty – A formal agreement between two states signed by official representatives of each state. It may be “law-making” and states the declared intention of the signatories to make or amend their internal laws to give effect to the agreement. The Bern Convention is an example of such as a treaty. Other treaties are just contracts between the signatories to conduct themselves in a certain way or to do a certain thing. These latter type of treaties are usually private to two or a limited number of states. So these agreements may be binding only through the International Court of Justice.
See also “Law of Contracts”