The difference between a bill and a law lies primarily in their stages of legislation. A bill is a proposed idea for new legislation that is presented to a legislative body for consideration. If the bill successfully passes through the necessary stages, including debates and votes, it may be signed by an executive (like a president) to become a law. In contrast, a law is a formally enacted rule that governs conduct and is enforceable by the state. Thus, while all laws start as bills, not all bills become laws.