Net Present Value
Net Present Value is a method to estimate the current value of future cash flows. In its simplest form, Net Present Value applies a discount rate to a future cash flow number and the product is the Net Present Value.
The discount rate may have many components; Internal Rate of Return (IRR), Cost of Capital, Cost of Debt, Risk, estimated inflation and risk.
Suppose you lent $100.00 to Person A. It is to be repaid within one year. You would like a return of 5% on your money you expect inflation to be 2%, and your assessment of risk for this person leads you to add 1% to the discount rate. This means you would assign a discount rate of 8% to this loan. If this person approached you suggesting, I will give you $90.00 today to discharge my loan, you would counter that you needed at least $92.59. (92.59 x 1.08 = $100.00)
Usually a corporation will use a Weighted Average Cost of Capital as a discount rate when NPV is the appropriate method of evaluating an invesment or capital expenditure.