The long-run supply curve the relationship between the quantities supplied on the horizontal axis and the price on the vertical axis.

The long-run supply curve indicates the price and the general production of a particular economy (real GDP). The curve indicates the long-run changes in prices and their relation to change in the supply quantity at that given period. A price change may change the quantity supplied according to the law of supply. When prices increase, supply quantity also increases, and vice versa. However, in the long-run, price changes are recognized better than in the short-run. Mostly, prices are constant in the short-run and vary in the long-run due to changes in technology, demand, competition, prices, etc.