Can you describe methods to calculate NPV & IRR and explain its key features?

NPV Calculation Method

PV = Future value/(1 + i)`n

When we calculate the Present Value (P.V) of all or different years then we sum or add the whole P.V's, the sum of all PV's will become NPV

NPV = FV/(!+i)`1 + F.V /(1+i)`2+.....................+F.V/(1+i)`n

IRR Calculation Method

The Internal Rate of Return is a rat of return used in capital budgeting to compare the profitability of investment, it is also known as discounted cash flow.  

A rate of return on which the NPV become zero is an internal rate of return.