In the common law tradition, a large part of the law was never enacted by any legislature. Contract, tort, much of property and trusts — these grew from centuries of decided cases, each judgment reasoning from the ones before it. The legislature can always override the case law by statute, but until it does, the cases are the law.
This is the deep contrast with the civil law tradition of continental Europe, where comprehensive codes state the law and court decisions are, in principle, only applications of it. Common law judges are open lawmakers within their sphere; civilian judges are, formally, code-appliers. In practice the two traditions have converged considerably — common law countries legislate heavily, and civilian courts build de facto precedent.
Nine provinces and the territories are common law jurisdictions. Quebec's private law follows the Civil Code of Québec instead — making Canada bijural, with the Supreme Court sitting atop both traditions.