Public law is a theory of law governing the relationship between individuals (citizens, companies) and the state. Under this theory, constitutional law, administrative law and criminal law are sub-divisions of public law. This theory is at odds with the concept of constitutional law, which requires all laws to be specifically enabled, and thereby sub-divisions, of a constitution.

Generally speaking, private law is the area of law in a society that affects the relationships between individuals or groups without the intervention of the state or government. In many cases the public/private law distinction is confounded by laws that regulate private relations while having been passed by legislative enactment. In some cases these public statutes are known as laws of public order, as private individuals do not have the right to break them and any attempt to circumvent such laws is void as against public policy.

In the "English" provinces of Canada, the term private law is also known as English Common Law, or just common law. These are judge-made laws. Public Law is that law which is passed by either the provincial legislatures or by the federal Parliament. In Quebec, private law is basically the civil code of Quebec, considered to be the primary source of private law. These laws are interpreted by judges, but this within the ambit of the codal provisions that have been enunciated by the legislators.