International law comprises rules governing relations between sovereign states and individuals of different states. It can be classified into public international law, which relates to laws between states, and private international law, concerning relationships between individuals of different states. International law is significant as it regulates state conduct and maintains laws regarding individuals, covering areas like refugee laws, narcotics treaties, and human rights. While international law has limitations due to state sovereignty, it can still play an important role in regulating global affairs through treaties and conventions.