A more thorough explanation:

International conventions are agreements between countries. They are also called treaties, agreements, compacts, or contracts between states. These conventions can be between two or more countries. When it is between two countries, it is called a bilateral treaty. When it is between more than two countries, it is called a plurilateral or multilateral treaty.

A common type of international convention is a bilateral investment treaty (BIT). This is an agreement between two countries that establishes the terms and conditions for private investment by nationals and companies of one state in another state.

Another example is the Paris Agreement, which is a multilateral treaty between 196 countries to combat climate change. It sets out a framework for countries to work together to limit global warming and its impacts.

Just because a country signs an international convention, it does not mean that it is automatically binding law. In the United States, for example, the convention must be self-executing or Congress must pass legislation to make it binding.

If you want to learn more about international conventions, you can read articles like this one from the Harvard Law Review, this research guide from Berkeley Law, or this article from the UCLA Law Review.