A shift in the demand curve indicates

A shift in the demand curve refers to a change in the entire demand schedule, caused by a factor other than the price of the commodity. This means that at every price, the quantity demanded has changed. For instance, a change in consumer preferences, income, or the prices of substitute or complementary goods can shift the demand curve to the right or left. A shift to the right indicates an increase in demand while a shift to the left indicates a decrease in demand. Therefore, a shift in the demand curve represents a change in demand, which is different from a change in quantity demanded, which is caused by a change in the price of the commodity, leading to a movement along the same demand curve.