Common law and statutory law are two systems of law used in the American judicial system. Common law is based on prior court decisions while statutory law is made by the legislature.
Common law, also known as case law, allows judges to render decisions based on the rulings of earlier cases. Common law is guided by the regulations set forth in federal or state statutes, but it does not rely exclusively on those written laws.
Statutory law refers to the written law established by the legislative branch of the government. Statutes may be enacted by both federal and state governments and must adhere to the rules set in the Constitution. Proposed statutes are reviewed by the legislature prior to being enacted into law.