"Taxes" refers to the financial obligation placed on a business or individual by a governmental agency as the result of some taxable event. If a business has employees, the business must withhold a portion of the employee's pay for state and federal income tax purposes. The business also typically pays a payroll tax. Capital gains realized from the sale of real estate, securities, or other property require payment of a capital gains tax. In most states, a sales tax is paid when an item is purchased. The sales tax is generally a percentage of the sale price of the item. The amount of the tax is based upon the value of the financial transaction subject to the tax. Generally, it is a percentage of the value of the underlying financial transaction. However, various credits, deductions, and exemptions come into play to reduce the actual tax liability. These are usually calculated on government forms called "tax returns" and, in some cases, "schedules." If prior withholdings are in excess of the actual tax liability, as shown by the tax return, then the excess is refunded to the taxpayer. If prior withholdings are inadequate to cover tax liability, then the taxpayer must pay the difference.