The project profitability index and the internal rate of return:?

Profitability index indicates how much you earn profit for each $1. On the other hand internal rate of return means how much you are for each$100. Both show the same evaluation. Both have good inter relation with payback period. If the project gain higher PI or IRR then payback period comes shorten. On the contrary if PI & IRR is lower project take much time to acquire or touch its payback period. Same happened for NPV