(i) Substitue goods are those goods which can be used in place of one another to satisfy a particular want whereas complementary goods are those goods which are used together to satisfy a particular want.
(ii) Substitue goods have competitive demand whereas complementary goods have joint demand.
(iii) Price of one substitute good has a positive relationship with qunatity demanded of another substitute good whereas price of one complementary good has a negative relationship with demand of another complementary good.
