Demand

Willingness and ability to buy goods and services

Individual Demand

Willingness and ability to buy goods and services of one individual in a market

Market Demand

Willingness and ability to buy goods and services of all individuals in the market

Contraction in Demand

Decrease in quantity demanded due to an increase in price

Extension in Demand

Increase in quantity demanded due to an decrease in price

Increase in Demand

Increase in quantity demanded due to factors other than the price. e.g. Increase in Income. Right shift in the demand curve.

Decrease in Demand

Decrease in quantity demanded due to factors other than the price. e.g. Decrease in Income. Left shift in the demand curve.

Supply

Willingness and ability to sell goods and services

Individual Supply

Willingness and ability to sell goods and services by one firm in a market

Market Supply

Willingness and ability to sell goods and services by all firms in a market

Extension in Supply

Increase in quantity supplied due to increase in price

Contraction in Supply

Decrease in quantity supplied due to decrease in price

Increase in Supply

Increase in the quantity supplied due to factors other price. e.g. Decrease in Production cost. Right shift in the supply curve.

Decrease in Supply

Decrease in the quantity supplied due to factors other price. e.g. Increase in Production cost. Left shift in the supply curve.

Market Equilibrium

It is when quantity demanded is equal to quantity supplied at a given price.

Market Disequilibrium

It is when quantity demanded is not equal to quantity supplied at a given price.