Distinguish between substitution effect and income effect

Answer

The substitution effect states that when the price of a good decreases, consumers will substitute away from goods that are relatively more expensive to the cheaper good or Substitution effect is increase in demand of a commodity whose price is said to fall as compared to its substitutes whose prices are said to be constant. Or

The income effect states that when the price of a good decreases, it is as if the buyer of the good’s income went up. Or income effect refers to the increase in demand of a commodity due to increase in real income or purchasing power as a result of price fall of the commodity.