Planning is the primary function of management and involves determining objectives and courses of action in advance. It includes establishing objectives, considering alternatives, and selecting the best option. There are different types of plans like standing and single-use, long and short-range, and formal and informal. The planning process involves forecasting, identifying alternatives, evaluating options, selecting the best alternative, developing supporting plans, implementing, and controlling. Planning provides direction, promotes innovation, aids decision making, reduces waste, and helps manage risk and uncertainty.