Demand curve movement refers to changes in price that affect the quantity demanded. A demand curve shift refers to fundamental changes in the balance of supply and demand that alter the quantity demanded at the same price. For example, you may be willing to buy 10 apples at $1. If the grocery store drops the price to $0.75, then that demand curve movement means you might buy 15 apples instead of 10. If you get a raise at work, that demand curve shift may mean you're willing to buy 15 apples at $1 and 20 apples at $0.75.