An income tax is a tax imposed on individuals or entities (taxpayers) that varies with their respective income or profits (taxable income). Many jurisdictions refer to income tax on business entities as companies tax or corporate tax. Partnerships generally are not taxed; rather, the partners are taxed on their share of partnership items. Tax may be imposed by both a country and subdivisions. Most jurisdictions exempt locally organized charitable organizations from tax. Income tax generally is computed as the product of a tax rate times taxable income. The tax rate may increase as taxable income increases (referred to as graduated or progressive rates). Taxation rates may vary by type or characteristics of the taxpayer. Capital gains may be taxed at different rates than other income. Credits of various sorts may be allowed that reduce tax. Some jurisdictions impose the higher of an income tax or a tax on an alternative base or measure of income.