Demand

(1) As a term in economics, demand means the amount of a commodity (good or service) that would be purchased at a given price. An associated term is [DEMAND FUNCTION,] which presents the demand-versus-price relationship. A demand function for a given commodity is compared with a corresponding [SUPPLY function ] to determine the EQUILIBRIUM PRICE: a price at which the supply offered matches the demand. (2) In another usage, demand means the amount of a commodity required for a certain purpose. It often relates to the future, as in: "the world energy demand in the year 2030 will be 35 terawatts." Implicit in this statement is that the price of energy as well as other economic conditions will be such that 35 terawatts will be consumed (purchased) if technically available. (IIASA)