Aggregate supply refers to the total amount of goods and services that firms in an economy are willing and able to produce at a given price level and in a given period of time. It is the total supply of all goods and services in an economy that are produced and sold in a given period of time. The level of aggregate supply is determined by factors such as the availability of resources, technology, and the level of production capacity in the economy. The aggregate supply curve shows the relationship between the price level and the level of aggregate output that firms are willing and able to produce. It is upward sloping in the short run and vertical in the long run. Changes in aggregate supply can have significant effects on the overall performance of an economy, including inflation, employment, and economic growth.