The government of Illinois, under the Constitution of Illinois, has three branches of government: executive, legislative and judicial. The executive branch is split into several statewide elected offices, with the Governor as chief executive, and has numerous departments, agencies, boards and commissions. Legislative functions are granted to the General Assembly, composed of the 118-member House of Representatives and the 59-member Senate. The judiciary is composed of the Supreme Court and lower courts.
The government of Illinois has numerous departments, agencies, boards and commissions, but the code departments, so called because they're established by the Civil Administrative Code of Illinois, provide most of the state's services:
Department on Aging
Department of Agriculture
Department of Central Management Services
Department of Children and Family Services
Department of Commerce and Economic Opportunity
Department of Corrections
Department of Employment Security
Department of Financial and Professional Regulation
Department of Healthcare and Family Services
Department of Human Rights
Department of Human Services
Department of Juvenile Justice
Department of Labor
Department of the Lottery
Department of Natural Resources
Department of Public Health
Department of Revenue
Department of State Police
Department of Transportation
Department of Veterans' Affairs