Accordingly, each state has co-existing Federal and State Courts. The state courts enforce the state laws and the federal courts enforce the federal laws. Federal Courts also sometimes hear state law cases between residents of multiple states. Our law is derived from both statutes and common law.
Statutes are laws passed by our elected officials.
In California, our statutes are found in the California Constitution and the California Codes. Federal statutory law is found in the U.S. Constitution and the U.S. Codes. On some issues, California law is limited by federal law. Common law permits the Courts to apply reasoned principals to situations not addressed by statutes. Of course, Courts also interpret the meaning of the statutes.