What is deposit insurance and how to insure it?

Original insurance: insurance purchased by customers from insurance companies, no matter what kind, is called original insurance.

Reinsurance: Insurance purchased by an insurance company for the original insurance of its customers in order to spread the operational risks that may be brought to the company is called reinsurance. Therefore, reinsurance is also called insurance. Compared with the original insurance, reinsurance can only be purchased by insurance companies to share the risks of insurance companies.

* * * Co-insurance: refers to the insurance that an insurance company underwrites the subject matter of insurance together with a relatively large risk unit in order to spread its own underwriting risks. The difference between reinsurance and reinsurance lies in the different ways of risk diversification. In insurance, risks are vertically dispersed, while in insurance, risks are horizontally dispersed.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.