Independent agencies of the United States federal government are those agencies that exist outside of the federal executive departments (those headed by a Cabinet secretary). However, most independent agencies are part of the executive branch, with only a few being part of the legislative or judicial branches. Established through separate statutes passed by the Congress, each respective statutory grant of authority defines the goals the agency must work towards, as well as what substantive areas, if any, over which it may have the power of rulemaking. These agency rules (or regulations), while in force, have the power of federal law.