Specific taxes are of a fixed amount based on a number, or standard of weight or measurement. Ad valorem taxes are based on a fixed proportion of the value of the property with respect to which the tax is assessed. They require an appraisal of the taxable subject matter's worth.
Income tax meets the broadest definition of a property tax.
The term, however, is often limited to taxes based on real property. See Real Property . The most frequent use of property taxes in the U.S. is by municipal governments, authorized to generate necessary revenue in this fashion under state law. See Income Tax .