|total number of accounting periods|
i= 0, 1, 2, 3, ...
running number of accounting period (usually 1 year)
|discounted value of total cash generated over "n" accounting periods|
The main idea of DCF is that value of cash today is deemed by the majority of cash owners as higher than value of future cash because it is already in hand and it can be spent by owner or can be invested in readily available low-risk investment market opportunities and assure a certain profit. While future cash may not happen at all or may be lower than returns from readily available low-risk investment.
The corresponding discount of the cash value over time is controlled by Discount Rate (usually denoted as r) which is normally set along with Weighted Average Cost of Capital (WACC).
Investor normally would like to compare different investment opportunities and give early returns more weight and as such comparing DCF rather than FCF.
DCF is used to calculate Net Present Value (NPV) to prioritise investment projects.