This presentation discusses concepts of cost and cost analysis. It defines different types of costs such as opportunity cost, implicit cost, explicit cost, sunk cost, accounting cost, and economic cost. It explains why opportunity cost is important for decision making and the difference between sunk and opportunity cost. The presentation also covers the theory of cost in the short run vs long run. It defines variable costs, fixed costs, and different types of short run costs including total, average, and marginal cost functions.