Local governments are a subdivision of state government; therefore the state has a vested interest in the operation of local governments.  The state has a prescribed set of accounting codes (Chart of Accounts) in which the local governments use to budget and expense their cost of operations

In county government, each of the major operations—roads, education, and general government—operate under a separate fund maintained through the county trustees’ office. These funds are like subsidiary businesses of a holding company. Each fund has its separate accounting and budgeting system and records. A budget is approved by fund and function with a property tax rate set for each fund that needs it. Tennessee counties usually operate under the following funds: