Public international law is the legal system that regulates relations between states in the international community. This type of law includes principles and rules that regulate transactions between states and define their rights and duties. Public international law aims to promote international peace and security and to achieve international cooperation in areas such as human rights, environmental protection, international trade and international dispute resolution. Public international law includes sources of international law such as international treaties, customary laws, and international judicial decisions. Public international law also evolves through new interactions and challenges facing the international community.