ROI, which stands for Return on Investment, is a financial metric used to evaluate the profitability or efficiency of an investment. It measures the return or gain generated on an investment relative to its initial cost. ROI is expressed as a percentage and provides valuable insights into the performance and success of an investment.

ROI helps investors and businesses assess the effectiveness of their investment decisions by comparing the amount gained or lost with the initial investment. It allows for the comparison of different investment opportunities and helps determine which ones are more favorable in terms of returns.