When you learn a tactic, you know one way of doing something. But when you understand a principle (the overall strategy), you understand that several tactics can be applied to achieve the desired result.
Tactics are how you do something. They are techniques used to get the job done. Strategy is why you’re doing something. Strategy is looking at the big picture. You need both to get to where you want to be, but it is important to not focus too heavily on one over the other. Only using one tactic when others would serve you better would be foolish. You need to look at the overall strategy to determine which is the best tactic to be used at a certain time. At the same time, spending too much time on strategy (planning) isn’t going to get the job done. At some point the plan has to be put into action.
Work on understanding all aspects of what you’re focusing on. You should work to know the what’s, how’s, and why’s of a subject and you will be able to plan and act accordingly.