Strategy is a general, undetailed plan of action, encompassing a long period of time, to achieve a complicated goal. Strategy, as a way of action, becomes necessary in a situation when, for the direct achievement of the main goal, the available resources are not enough. The task of strategy is an efficient use of the available resources for the achievement of the main goal. Tactics is the tool to implement strategy, and is subordinated to the main goal of strategy.
Detailing it further, strategy is all about gaining a position of advantage over adversaries or best exploiting emerging possibilities. As there is always an element of uncertainty about the future, strategy is more about a set of options than a fixed plan. Henry Mintzberg from McGill University defined strategy as "a pattern in a stream of decisions" to contrast with a view of strategy as planning while Max Mckeown argues that "strategy is about shaping the future" and is the human attempt to get to "desirable ends with available means".