These two parties can be two nations or two international organizations or one nation and one international organization or two people. It is possible that a bilateral contract involves more than two parties; Thus, each bilateral treaty between Switzerland and the European Union (EU) has seventeen parties. The parties are divided into two groups: the Swiss (“on the one hand”) and the EU and its member states (“on the other side”). The treaty establishes rights and obligations between Switzerland and the EU and the Member States for several years – it does not create rights and obligations between the EU and its member states.   In 1960, Spain signed an agreement with the OECD to promote measures to improve the economic development and social well-being of people around the world. Note that it is not the name (an agreement, a pact, a convention, etc.), but the content of an agreement between two parties that constitutes a bilateral treaty. The agreements between Egypt and Israel, signed in September 1978 by Camp David, the Geneva Protocol or the Biological Weapons Convention, are not examples.  For example, if someone offered to drive you to work on Mondays and Tuesdays in exchange for your promise to return favors on Wednesdays and Thursdays, a bilateral contract would be concluded, which binds the two of you as soon as you have thought about these conditions. But if the same person offered to pay you $10 a day that you would take him to work, a unilateral contract would be formed, which would only hire the promisor until you took him to work on a given day.
A bilateral contract (also called a two-year contract) is a contract that exists exclusively between two state entities. It is an agreement between two parties, drawn up in writing and signed by representatives of the parties. Treaties can be substantive and complex, on a wide range of issues such as territorial boundaries, trade and trade, political alliances and much more. The agreement is then generally ratified by the legislative authority of each party or organization.  Any agreement with more than two parties is a multilateral treaty. Like a treaty, it is called a contract. As with any other contract, it is a written agreement that is typically formal and binding.  An agreement between two parties can enter into force in two ways. The first is that both parties have fulfilled certain conditions of adherence to the agreement. The second way to enter into force is for the two parties to decide to be linked by the agreement from a certain point of time.