CBSE Class 11-commerce Answered
Change in quantity demanded is when demand for a commodity changes due to change in is own price. This results in the movement along the demand curve i.e. the extension of demand caused by a decrease in the price of the same good and the contraction of demand caused by an increase in the price of the same good.
Change in demand is when demand for a commodity changes due to change in other fators other than price. As a result there is a shift in the demand curve i.e. the decrease in demand or the backward shift in the demand curve caused by a change in factors other than the price of the good and an increase in demand or a forward shift in the demand curve caused by a change in factors other than the price of the good. Example change in income.