Return on investment (ROI) refers to the value that should be returned through investment, that is, the economic return that an enterprise receives from an investment activity. Return on investment = (annual profit or average annual profit/total investment) × 100%. It can be seen from the formula that when the total investment remains unchanged, the return on investment is directly proportional to the company's profit. Therefore, it can be simply understood that the higher the return on investment, the stronger the company's profitability. If the return on investment is 0, indicating that the company has no profit. The return on investment in different industries is different, mostly between 5% and 20%. Generally speaking, the higher the return on investment, the better, but in fact the return on investment is also related to the investment time. For the same investment amount, the longer the investment time, the higher the return on investment.