In economics, the curve showing the maximum price consumers are willing to pay for each quantity of a good is called the demand curve.
A demand curve represents the relationship between a good’s price and the quantity consumers are willing and able to buy, with other relevant conditions held constant. In the usual model, it slopes downward: lower prices are associated with larger quantities demanded.
The curve can also be interpreted as a marginal willingness-to-pay schedule. The height of the curve at a quantity indicates the value the marginal buyer places on that unit. This interpretation helps economists analyze consumer surplus and the effects of taxes or price controls.
A movement along the curve follows a change in the good’s own price. Changes in income, preferences, related-good prices, or the number of buyers shift the entire curve instead.