What distinguishes a movement along the supply curve from a shift in the supply curve?

A movement along the supply curve occurs as a direct response to changes in the price of the good or service itself, illustrating the law of supply, which states that all else being equal, an increase in price typically leads to an increase in the quantity supplied. This scenario can be visually represented by moving up or down a specific supply curve, indicating that suppliers are reacting solely to price variations.

In contrast, a shift in the supply curve happens due to external factors that affect supply, which are not related to the price of the product. These factors can include changes in production costs, technology advancements, changes in the number of suppliers, or shifts in government policies or regulations. When the supply curve shifts to the right, it indicates an increase in supply at every price point; conversely, a shift to the left indicates a decrease in supply.

This understanding clarifies that only price changes lead to movements along the supply curve, while shifts in the curve itself are caused by broader, non-price-related factors.