What is a home rule unit?
In general, a home rule unit is either a county that has a chief executive officer elected by the electors of the county or a municipality that has a population of more than 25,000. Municipalities of 25,000 or less may elect by referendum to become a home rule unit. For more information, see PTAX-1002-8, Local Governments' Guide to Tax Allocations, Home Rule Sales Taxes.