Underwriting profit, in common parlance, is to charge a premium of 100 yuan, excluding compensation and various expenses, and the rest of the money underwrites profit;
Investment income is to invest with the collected insurance premium to generate income.
In most insurance companies, the investment profit is far greater than the underwriting profit. There are many reasons. With more and more insurance objects in the market and more and more fierce competition, insurance companies are almost unprofitable in underwriting, and some even lose money. As for investment, it also depends on the year. In a good year, the overall investment is improving and the profit is acceptable.
Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.