Insurance or assurance, device for indemnifying or guaranteeing an individual against loss. Reimbursement is made from a fund to which many individuals exposed to the same risk have contributed certain specified amounts, called premiums. Payment for an individual loss, divided among many, does not fall heavily upon the actual loser. The essence of the contract of insurance, called a policy, is mutuality. The major operations of an insurance company are underwriting, the determination of which...