Pairs of goods that are used in place of each other such as movie ticket and DVD rental.
Price of B increase, Demand for A increase.
Price of B decrease, Demand for A decrease
• The demand curve for one goods can be affected by a change in the price of another related good.
Complements
Pair of goods that are used together such as gasoline and automobiles or computer and software.
Price of A increase, Demand for B decrease.
Price of A decrease, Demand for B increase.