Derived demand and Demand schedule:
Derived demand is where the demand for a final product leads to the demand for a second product which is used to produce this final product - i.e. if the demand of a product is not for its own sake, but for the manufacture of another product which is in demand. For example, the demand for furniture derives the demand for wood; the demand for petrol derives the demand for crude oil.
Demand schedule is a table or a list of various prices of a commodity and the corresponding quantities that would be purchased at a particular time period, when all other demand factors remain constant. For example, the table below shows the demand schedule for a commodity sold in bags. Column 1 of the Table 1 shows a set of prices of the commodity and column 2 shows the quantities of it that consumers are willing and able to buy at each price.