Early societies relied on a gift economy based on favours. Later, as commerce developed less permanent human relations were formed, depending more on transitory needs rather than enduring social desires. Although such distinctions have no contemporary semantic weight, certain sectors prefer client while more stable, repeat business operations tend to prefer customer
The term client is derived from Latin clientem or clinare meaning "to incline” or “to bend," and is related to the emotive idea of closure. It is widely believed that people only change their habits when motivated by greed and fear Winning a client is therefore a singular event, which is why professional specialists who deal with particular problems tend to attract one-time clients rather than regular customers.
Clients who habitually return to a seller develop customs that allow for regular, sustained commerce that allows the seller to develop statistical models to optimize production processes (which change the nature or form of goods or services) and supply chains (which changes the location or formalizes the changes of ownership or entitlement transactions).
A customer may or may not also be a consumer, but the two notions are distinct, even though the terms are commonly confused. A customer purchases goods; a consumer uses them. An ultimate customer may be a consumer as well, but just as equally may have purchased items for someone else to consume. An intermediate customer is not a consumer at all. The situation is somewhat complicated in that ultimate customers of so-called industrial goods and services (who are entities such as government bodies, manufacturers, and educational and medical institutions) either themselves use up the goods and services that they buy, or incorporate them into other finished products, and so are technically consumers, too. However, they are rarely called that, but are rather called industrial customers or business-to-business customers.Similarly, customers who buy services rather than goods are rarely called consumers.
Geoff Tennant, a Six Sigma consultant from the United Kingdom, uses the following analogy to explain the difference: A supermarket's customer is the person buying milk at that supermarket; a not-customer buys milk from a competing supermarket, whereas a non-customer doesn't buy milk from supermarkets at all but rather "has milk delivered to the door in the traditional British way".
Before the introduction of the notion of an internal customer, external customers were, simply, customers. Quality-management writer Joseph M. Juran popularized the concept, introducing it in 1988 in the fourth edition of his Quality Control Handbook . The idea has since gained wide acceptance in the literature on total quality management and service marketing; and many organizations as of 2016 recognize the customer satisfaction of internal customers as a precursor to, and a prerequisite for, external customer satisfaction, with authors such as Tansuhaj, Randall & McCullough 1991 regarding service organizations which design products for internal customer satisfaction as better able to satisfy the needs of external customers. Research on the theory and practice of managing the internal customer continues as of 2016 in a variety of service-sector industries.