Cluster sampling is a statistical method of sampling that can be used to obtain a representative sample of a group. It is a type of sampling that divides a population into mutually exclusive groups, or clusters, and then randomly samples from those clusters. This method is useful in situations where it is impossible to obtain a complete list of members of the population, or when the cost or time involved in obtaining such a list is prohibitive. Cluster sampling is especially beneficial when sampling from a large population, as it is a more efficient and cost-effective way of obtaining reliable data.