Whats the difference between common law and statutory law?

Common law is "judge-made law." It's essentially the same as legal precedent or "stare decisis." Common law is the body of law created when judges interpret and apply existing law to the cases before them, which future courts are bound to follow. Once upon a time, judges literally made up the law this way, over the course of history.

Statutory law is the law created by statute. It comes from law-making bodies like legislatures, and is simply written down into a code or statute book.

We still have both, except that judges no longer entirely make up law, (or so we hope) but rather follow statutes and the common law or "case law" interpreting it. Sometimes courts are "bound" by the precedent set by prior decisions, and sometimes they are not.

common law is assumed..statutory means its spelled out on the books