This report delves into fundamental microeconomic concepts, exploring their implications for business decision-making. It examines the principles of international trade, including absolute and comparative advantage, and analyzes the relationship between price and quantity demanded, highlighting exceptions to the law of demand. The report further investigates the connection between marginal and average product, explaining their relationship through the lens of diminishing marginal returns. Finally, it addresses the misconception that firms should leave an industry when making zero profits, clarifying the distinction between accounting and economic profits and the concept of normal profits in perfect competition.