Input prices refer to the costs incurred by producers to acquire resources and factors of production essential for manufacturing goods or delivering services. These costs include wages for labor, prices of raw materials, and costs associated with machinery and technology.

Fluctuations in input prices significantly influence the supply curve. When input prices rise, the production cost increases, making it less profitable for producers to supply the same quantity at the existing price. This leads to a decrease in the supply, causing a leftward shift in the supply curve. Conversely, when input prices fall, production costs decrease, encouraging producers to supply more at the existing price. This results in an increase in supply and a rightward shift in the supply curve.

The shifts in the supply curve due to changes in input prices illustrate producers' responsiveness to production cost variations. Producers aim to maximize profits, and any changes in input prices directly affect their profit margins. Consequently, they adjust their production levels, which is reflected in the shifts in the supply curve.