United States federal government chartered and owned corporations are a separate set of corporations chartered and owned by the federal government, which operate to provide public services, but unlike the federal agencies (Environmental Protection Agency, Bureau of Indian Affairs), or the federal independent commissions (e.g., the Federal Communications Commission, the Nuclear Regulatory Commission, etc.), they have a separate legal personality from the federal government, providing the highest level of political independence. They sometimes receive federal budgetary appropriations, but some also have independent sources of revenue.