Reinsurance is insurance that an insurance company purchases from another insurance company to insulate itself from the risk of a major claims event. With reinsurance, the company passes on ("cedes") some part of its own insurance liabilities to the other insurance company. The company that purchases the reinsurance policy is referred to as the "ceding company" or "cedent". The company issuing the reinsurance policy is referred to as the "reinsurer". In the classic case, reinsurance allows insurance companies to remain solvent after major claims events, such as major disasters like hurricanes or wildfires. In addition to its basic role in risk management, reinsurance is sometimes used to reduce the ceding company's capital requirements, or for tax mitigation or other purposes.

Insurance is a means of protection from financial loss in which, in exchange for a fee, a party agrees to compensate another party in the event of a certain loss, damage, or injury. It is a form of risk management, primarily used to protect against the risk of a contingent or uncertain loss.