Discount rate
The rate the Federal Reserve charges for lending to commercial banks (like the bank rate in Britain). In addition, a discount rate is used by any investor or company trying to calculate the present value of a series of future cashflows. Since money in the future is worth less than money today, these cashflows must be reduced or discounted. The chosen discount rate, usually related to current interest rates or bond yields, can make a big difference to the net present value. For more, see this article. See also time value of money.