Final answer:
Moving along a demand curve occurs when the only variable that changes is the price of the product, while all other determinants of demand are held constant under the ceteris paribus assumption.
Step-by-step explanation:
Moving along a demand curve, implies that we are looking at the change in quantity demanded resulting from a change in the good's price, with the assumption that all other factors affecting demand (ceteris paribus) remain constant. This means that income, tastes, expectations, and prices of related goods do not change. The only factor that changes is the price of the good itself, which is represented on the vertical axis of the demand curve. Therefore, when we move along a demand curve, all non-price determinants of demand are held constant.
Factors such as changes in consumer preferences, demographic shifts, income levels, and the prices of substitutes or complements would shift the entire demand curve, not just move along it. These changes are represented by a new demand curve rather than a movement along the existing curve.