Answer:
Blu-ray discs are normal goods and DVDs are inferior goods.
Step-by-step explanation:
A normal commodity is a product that is experiencing a growth in its consumption due to the increase in the earnings of the customers. A standard good, sometimes named a required good, does not relate to the price of the commodity but rather to the degree of demand for both the product in response to rises or decreases in wages.
On the other hand, An inferior product refers to the product whose value reduces as customer wages increase, unlike regular products in which the reverse is observed. Standard products are those products to which output grows as market spending decreases.