Substitute resource: A substitute resource can be used interchangeably with another resource in production. For example, if hamburgers can be produced using either chicken or beef, chicken and beef are substitute resources.
Supply of complementary resource: The amount of a complementary resource that producers are willing and able to provide at various prices.
Joint demand: Joint demand refers to when two goods are demanded together because they are complements. For example, cars and gasoline have joint demand since cars require gasoline to operate.