A trading plan is crucial because it provides a structured approach to trading, helping you make informed decisions and avoid emotional reactions. My trading plan outlines my goals, risk tolerance, entry and exit criteria, and strategies. This helps me remain disciplined and focused.
To me, trading plan and trading strategy are still the same thing you are talking about because all these things you mention here are things that we also use when we want to mention the strategy that has been used in trading as a successful trader, so I think you are talking about strategy. However, plan is very important for anything we are doing; if it lacks a plan, it will later fail. In trading, a plan is very good. Without a plan, the way trading works, a trader will break or always lose if he or she enters the market, but if there is a plan, that will be a guide for such a trader to operate in the market.