Insurance, in law and economics, is a form of risk management primarily used to hedge against the risk of a contingent loss. Insurance is defined as the equitable transfer of the risk of a loss, from one entity to another, in exchange for a premium, and can be thought of as a guaranteed and known small loss to prevent a large, possibly devastating loss. An insurer is a company selling the insurance; an insured or policyholder is the person or entity buying the insurance. The insurance rate is a factor used to determine the amount to be charged for a certain amount of insurance coverage, called the premium. Risk management, the practice of appraising and controlling risk, has evolved as a discrete field of study and practice.

Reinsurance is a means by which an insurance company can protect itself with other insurance companies against the risk of losses. Individuals and corporations obtain insurance policies to provide protection for various risks (hurricanes, earthquakes, lawsuits, collisions, sickness and death, etc.). Reinsurers, in turn, provide insurance to insurance companies. The company requesting the cover is called the cedant and the reinsurer can be called the ceded, although the latter term is not in common use.