Change in Quantity Demanded and Change in Demand

Change in Quantity Demanded:

This is a situation which is due to a rise or fall in the price of a commodity/service and it is described by a movement along the demand curve for the commodity/service.

Fig. 1: Movement induced by an increase in commodity’s own price

Fig. 2: Movement due to a decrease in commodity’s own price

Change in Demand:

This is a situation which is due to a variation in any determinant of demand other than commodity/service own price and it is described by a shift in the demand curve for the commodity or service.

Fig. 3: An increase in demand

Fig. 4: A decrease in demand