1. Social insurance is compulsory insurance required by the state. The state develops social insurance undertakings, establishes a social insurance system and sets up a social insurance fund, with the aim of enabling workers to get help and enjoy insurance benefits in old age, illness, work injury, unemployment and childbirth. China's "Labor Law" and "Social Insurance Law" clearly stipulate that it is the legal obligation of the employer to pay social insurance for workers, which is obviously compulsory by the state, and the employer shall not refuse to undertake this legal obligation under any excuse or reason.
Second, the housing provident fund refers to the long-term housing savings paid by state organs, state-owned enterprises, urban collective enterprises, foreign-invested enterprises, urban private enterprises and other urban enterprises, institutions, private non-enterprise units, social organizations and their employees.