Demand

Demand is a buyer's willingness and ability to pay a price for a specific quantity of a good or service. Demand refers to how much quantity of a product or service is desired by buyers at various prices.

Quotes

 * The economist’s “demand” is not the real demand; his “consumption” is an artificial consumption. For the economist, only that person really demands, only that person is a real consumer, who has an equivalent to offer for what he receives.
 * Friedrich Engels, Outlines of a Critique of Political Economy (1844)