Cost accounting and management involves analyzing costs based on their behavior and classification. There are three types of costs: variable costs that change with activity level, fixed costs that remain constant regardless of activity level, and mixed costs that have both fixed and variable components. It is important to properly identify costs as fixed or variable for business decisions around pricing, production levels, and profitability. Manufacturing costs include direct materials, direct labor, and manufacturing overhead, which make up the cost of goods manufactured. Period costs are non-manufacturing expenses.