Final answer:
The primary source of revenue for counties is property tax, while state governments raise substantial revenue from sales taxes and receive significant federal support.
Step-by-step explanation:
The primary source of revenue for counties is property tax. Counties in the United States typically rely on property taxes as a major financial resource to fund various local services such as public schools, infrastructure, and law enforcement. Although other sources of revenue exist, such as sales taxes, income taxes, and state block grants, property taxes provide the substantial share of local government revenue. In contrast, state governments derive a larger portion of their revenue from sales taxes and also receive significant funds through federal support and service charges.