Movement Along the Demand Curve:
Movement along the demand curve is driven by price. This is referring to the different points on the demand curve because a change in price makes a different point on the demand curve, not a point somewhere else on the plane. This is termed an increase or decrease in the quantity demanded.
Shifts in the Demand Curve:
Shifts in the demand curve are driven by demand shifter factors. There are 5 of these, and the factors cause a move in the whole curve either to the right or left. This is termed an increase or a decrease in demand.