A toy is any item that can be used for play. Toys are generally played with by children and pets. Playing with toys is an enjoyable means of training the young for life in society. Different materials are used to make toys enjoyable to both young and old. Many items are designed to serve as toys, but goods produced for other purposes can also be used. For instance, a small child may pick up a household item and "fly" it through the air as to pretend that it is an airplane. Another consideration is interactive digital entertainment. Some toys are produced primarily as collector's items and are intended for display only.