Planning involves determining a future course of action in advance. It is a primary managerial function that specifies objectives and selects alternative courses of action to achieve goals. There are different types and levels of plans, including strategic plans that apply to the entire organization, and operational plans that specify how strategic goals will be achieved. Effective planning requires establishing goals, developing alternative strategies, evaluating options, and implementing and reviewing derivative plans. However, planning also faces criticisms such as potentially creating rigidity or not adapting to dynamic environments.