In domestic law you can find a series of concepts that are not developed in the same way, in international law.
Such concepts are:
• In general, in each State there is a body or supreme set of rules called the Constitution. These are the rules from which the other rules of the system are derived.
• The regulation of behaviors is usually complemented by a secondary body of norms that, more or less completely, forms a system.
• Subjective Criterion:
In Public International Law, the subjects are national States and international organizations, and exceptionally, national States. In Private International Law, subjects are individuals, and exceptionally, national States and international organizations.