Why a dollar tomorrow is worth less than a dollar today
Present value answers "what is a future amount worth in today's money?" A dollar received in 10 years is worth less than a dollar today, because that dollar could otherwise be invested and grow in the meantime. The discount rate you choose represents that opportunity cost — the return you could reasonably earn elsewhere.
PV of a lump sum vs. PV of an annuity
PV mode discounts a single future amount back to today. PVA (present value of an annuity) mode discounts a series of equal, repeating payments — like a pension or a fixed settlement — back to a single lump-sum equivalent today. Use PVA when the future amount is not a single payment but a recurring one.
Why the discount rate you pick changes the answer so much
A higher discount rate produces a lower present value, since it assumes money grows faster elsewhere, making the future amount comparatively less impressive today. Try a conservative rate (e.g. a savings account yield) and a more aggressive one (e.g. expected market return) side by side to see how sensitive the result is to that single assumption.
Reading the schedule
The schedule breaks down how the discounting compounds period by period, so you can see exactly how much value is "lost" to time in each year rather than just the final total.
What this calculator does not cover
This handles a single lump sum or a series of equal payments — it does not compute Net Present Value (NPV) across multiple uneven cash flows (e.g. a business project with different cash flows each year). For that, you would need a dedicated multi-cash-flow NPV tool.