Strategy

A strategy is "A plan that aims to achieve certain short-, mid-, and/or long-term objectives" and "a plan for the conduct of a major phase, or campaign, within a conflict. A strategy is the basic idea of how the struggle of a specific campaign shall develop, and how its separate components shall fit together to contribute most advantageously to achieve its objectives." -Gene Sharp

In other words... strategy defines "how we turn what we have into what we need to get what we want." -Marshall Ganz

A grand strategy takes this definition one step further, referring to "a comprehensive perspective of how a goal is to be achieved, which includes a concept of what form(s) of action will be taken (nonviolent, violent, institutional or some combination), how resources (human, material, skills and knowledge, time) will be allocated, and how subordinate strategies (sometimes referred to as campaigns) will be applied to achieve intermediate objectives that support the attainment of the ultimate goal." -Gene Sharp

Good strategy is about making choices. Saying ‘yes’ to a few powerful options and saying ‘no’ to many others that are downright impossible or beyond the scope of what you can currently achieve. -The HUB's strategy workshop 

For tips on how to develop your strategy, see our wiki page What is the right way to come up with a campaign strategy?