Demand schedule

The demand schedule, depicted graphically as the demand curve,
represents the amount of goods that buyers are willing and able to
purchase at various prices, assuming all other non-price factors remain the same. The demand curve is almost always represented as
downwards-sloping, meaning that as price decreases, consumers will
buy more of the good.
 
Just as the supply curves reflect marginal cost curves, demand curves
can be described as marginal utility curves.
 
The main determinants of individual demand are the price of the good, level of income, personal tastes, the price of substitute goods, and the price of complementary goods.
 
The shape of the aggregate demand curve can be convex or concave,
possibly depending on income distribution.
 
As described above, the demand curve is generally downward sloping. There may be rare examples of goods that have upward sloping demand curves. Two different hypothetical types of goods with upward-sloping demand curves are a Giffen good (a type of inferior, but staple, good) and a Veblen good (a good made more fashionable by a higher price).