Demand for goods and services

• price of substitute goods
• price of complementary goods
• personal income
• tastes & preferences
• population size

Inferior goods: a good for which demand decreases as income rises

Normal good: a good for which demand increases as income rises

Composite demand: a good that is demanded for two uses

Derived demand: the demand for a good comes from the demand from another good.

A movement along the demand curve happens when the good's price changes.

A change in one of the conditions of demand shifts the demand curve to a new position