Strategy and tactics are often used interchangeably, which is actually an error. Although they are related, they do refer to different things.
Strategy is the approach taken overall in a battle. Strategies include rushing, turtling and camping, multi-prong attacks, etc. A strategy is the general approach to a conflict and while it may dictate what individuals on the battlefield will do it doesn’t, as a rule, tell them how to do it.
Tactics, on the other hand, are the specific actions you take on the field as an individual or as a small group to achieve the goals of the overall strategy. Will you use a pin and flank maneuver or two separate attacks? What pieces of cover will you choose to hide behind? How do you use that cover and, if necessary, leave it? What roles will the people on your team fill? When five opponents come barreling down the trail how will you ambush them? These are all tactical considerations and are generally solved on the fly, usually with the training or skills that the individuals involved have learned.
So in general, strategies are how you win the battle and tactics are how you solve the problems that you run into while executing the strategy. Which is more important? Well, both, really. I’m fond of saying, “a bad strategy executed perfectly will usually beat a perfect strategy executed badly.” In general a good strategy will help you win but tactics will keep you alive on the path to victory. They both rely on each other quite a bit.