This document discusses aggregate demand and supply. It defines key terms like GDP, GNP, AD, AS, SRAS and LRAS. It explains that AD is the total expenditure in an economy and AS is the total output supplied. SRAS has a positive slope due to sticky prices and wages. LRAS is vertical at full employment. The determinants of AD and AS are also outlined, such as how lower consumer spending reduces GDP and shifts AD left during recessions. Examples are given of how changes in trade, taxes, and the labor force impact the price level through movements along the AS-AD model.