This document provides an introduction and overview of insurance, including definitions of insurance, how it works, its importance, functions, and classes. Insurance is defined as an economic institution based on mutuality that is formed to establish a common fund to pay for unforeseen losses. It works by pooling risks and losses from many individuals into a large fund. The primary function of insurance is the equitable distribution of financial losses from a few insured individuals among the larger group of insured. There are two main classes of insurance: life assurance which covers human life contingencies, and general insurance which covers property and liability risks.