A  user is any person who uses a product or service to solve a problem or obtain  a benefit, whether or not they purchase it. Users may consume a product, as  in the case of a person using shampoo to clean their hair or eating a potato  chip to assuage hunger between meals. Users may not directly consume a  product but interact with it over a more extended period, like a family  owning a car, with multiple family members using it for many purposes over  several years. Products are also employed in producing other products or  services, where they may be referred to as input products. For example, steel  is an input product used in the production of automobiles. In product  development, the user refers to the target market for a particular product or  service. Companies often segment their markets by user type to better  understand and address the needs of each group. User types can be  distinguished by any number of characteristics, including age, gender, income  level, occupation, etc. Understanding users and user types are critical for  developing successful products and services.