The document discusses the concepts of short-run aggregate supply (SRAS) and long-run aggregate supply (LRAS). SRAS is upward-sloping in the short-run as nominal changes can affect real variables. LRAS is vertical in the long-run as nominal changes do not impact real factors. SRAS can shift due to factors like taxes, productivity, and wages. LRAS shifts from changes to labor, capital or technology. Together, SRAS and LRAS make up the overall aggregate supply curve.