Final answer:
A demand curve shows how changes in price affect the quantity demanded of a product, assuming all other factors remain constant.
Step-by-step explanation:
A demand curve illustrates the relationship between the price of a good or service and the quantity demanded by consumers. It typically slopes downward, indicating that as prices decrease, the quantity demanded increases. This fundamental economic concept is a key tool in understanding market dynamics and consumer behavior.
A demand curve shows how changes in price affect the quantity demanded of a product, assuming all other factors remain constant. When the economy expands and people's incomes rise, cars become more affordable and the demand for cars increases. This can be shown graphically by shifting the demand curve to the right, indicating a higher quantity demanded at each price.