Final answer:
Supply refers to the entire range of quantities that producers are willing and able to sell at different prices, while quantity supplied refers to a specific quantity that producers are willing and able to sell at a particular price. On a graph, changes in supply are represented by shifts in the supply curve, while changes in quantity supplied are represented by movements along the supply curve.
Step-by-step explanation:
The difference between the supply and the quantity supplied of a product, such as milk, is that supply refers to the entire range of quantities that producers are willing and able to sell at different prices, while quantity supplied refers to a specific quantity that producers are willing and able to sell at a particular price.
On a graph, the supply curve represents the relationship between the price of a product and the quantity that producers are willing and able to sell. When there is a change in supply, the entire curve shifts either to the right (increase in supply) or to the left (decrease in supply). This can be caused by factors such as changes in production costs or technology.
In contrast, a change in quantity supplied refers to a movement along the supply curve due to a change in price. As the price of a product increases, the quantity supplied by producers also increases, and vice versa. This movement along the supply curve is known as a change in quantity supplied.