The legislator makes policy or law while the regulator enforces policy or law. The regulator makes sure the policy or law is followed, and obeyed.

A regulator is a member of a government agency that regulates an area of human activity by codifying and enforcing rules and regulations for the benefit of the public at large. A regulator is not an elected official, but rather is appointed to his or her position. a legislator at the federal level serves in the United States Congress as a member of the House of Representatives or the Senate. Members of Congress are elected to office by the votes in their applicable state or district.