What does interest on social security principal mean?

Refers to the fixed interest income generated by individuals and units paying social insurance premiums. Social security principal interest cannot be directly extracted or transferred like bank deposits, but managed and used as a part of social security funds, resulting in some fixed interest rate income. Social security principal interest represents the funds actually paid by individuals and units when they participate in social insurance, including endowment insurance, medical insurance, unemployment insurance, work injury insurance and maternity insurance.