The "four funds" refer to pension insurance, medical insurance, unemployment insurance, housing provident fund, and public injury insurance.

Social Insurance (Social Insurance) refers to a social and economic system that provides income or compensation for people who have lost the ability to work, temporarily lost their jobs, or suffered losses due to health reasons. The main items of social insurance include pension insurance, medical insurance, unemployment insurance, work-related injury insurance, and maternity insurance.

The social insurance plan is organized by the government, forcing a certain group of people to use part of their income as social insurance taxes (fees) to form a social insurance fund. When certain conditions are met, the insured can receive benefits from the fund. Fixed income or loss compensation is a redistribution system whose goal is to ensure the reproduction of material and labor force and social stability.