Internal Rate of Return (IRR) is one of the key measures used by financial analysts and businesses to determine where to invest their money – should I buy this machinery and earn money from it over the next four years or should I open a new store with the expected revenue gains over time?

This article explains the difference between ROI and IRR by way of example.  The example is a $100,000 investment which resulted in $108,000 being received at the completion of the investment.