Final answer:
An insurer is an entity that writes insurance contracts, collects premiums, assesses risks, and pays out claims to policy holders who suffer specified losses. It is also responsible for administrative aspects of managing policies and claims.
Step-by-step explanation:
The best description of an insurer is 'any person, corporation, association or society that writes insurance contracts.' This definition encompasses entities that undertake the obligation to compensate policy holders or beneficiaries in case of certain losses in exchange for regular payments termed as premiums. Insurers are responsible for assessing the risk of potential claims and determining the premium amount necessary to cover these risks. They then pool these premiums together and use them to pay out claims to those who suffer from the specified financial losses indicated in their policies. Besides claims payments, insurers also face administrative costs, including hiring workers and processing claims, which are a significant part of the business.