By planning you can thus accomplish things that might otherwise look impossible. We all recognize that some decisions are more important than others, whether in their immediate impact or long term significance. Strategic decisions are the highest level. Here a decision concerns general direction, long term goals, philosophies and values. Whether to produce a low priced product and gain market share or produce a high priced product for a niche market would be a strategic decision.
Tactical decisions support strategic decisions.
They tend to be medium range, medium significance, with moderate consequences. Or if your company decided to produce a low priced product, a tactical decision might be to build a new factory to produce them at a low manufacturing cost. These are every day decisions, used to support tactical decisions. They are often made with little thought and are structured. Their impact is immediate, short term, short range, and usually low cost.