Final answer:
The demand faced by a firm is the quantity it can sell at a given price, while the demand faced by the industry is the total quantity all firms can sell at a given price.
Step-by-step explanation:
In economics, the demand faced by a firm refers to the quantity of a product that individual firm can sell at a given price. It is represented by the firm's own demand curve, which shows the relationship between the price of the product and the quantity demanded by consumers.
On the other hand, the demand faced by the industry refers to the total quantity of the product that all the firms in the industry can sell at a given price. It is represented by the industry's demand curve, which is derived by horizontally summing the individual demand curves of all the firms in the industry. The industry's demand curve reflects the overall demand for the product in the market.
For example, if there are three firms in the industry, each with its own demand curve, adding up the quantities demanded at each price level by all three firms gives the total industry demand curve.