The Vision of a company is the way that it views its products, its markets, its customers and itself. The Vision answers the simple question "Why are we here?". The Vision is a goal. It is not the same as a strategy; business strategy tells you how a company is going to achieve (or maintain) its Vision. The strategy is a plan, the tactics are how the plan will be executed and the Vision is the end-result.
Another way to think about strategy is to look at the vision statement and where you are now. If you haven't achieved your vision, your strategy is what you need to do. If you have achieved your vision (pretty rare in the business world), your strategy is how you will maintain that vision against the inevitable competition.