Answer: Difference: Pay-as-you-go system: Under the guidance of the recent principle of horizontal balance of payments, the pension of the retired generation is paid by the contributions of the working generation in a certain period of time.

Complete accumulation system: it is a financing method that is guided by the principle of long-term vertical balance of payments and characterized by the establishment of personal accounts, so that pensions directly come from the savings accumulation of social members themselves.

Partial accumulation system: under the premise of meeting the current payment demand through pay-as-you-go system, a certain reserve is set aside to meet the future expenditure demand. It is a financing method combining short-term horizontal balance principle with long-term vertical balance principle.