Insurance is a protection against financial loss from unexpected events. Insurance companies collect premiums from customers to create a pool of funds used to pay claims when losses occur. There are fundamental principles of insurance including utmost good faith, where customers have a duty to disclose all relevant information; insurable interest, where a person must have a financial stake in what is insured; and indemnity, where compensation aims to restore the insured to their pre-loss financial position. Other key principles are subrogation, where insurers can recover costs paid from liable third parties; contribution, which allows apportioning of claims across multiple applicable policies; and proximate cause, which determines the primary cause of a loss.