Definitions of vision, mission, strategy… I find these useful in my work.
Each organization uses these terms in slightly different ways, tailoring them to their needs. Some are often used interchangeably. There is no single right way, only a way that works. Yet the definitions below are ones that have worked well for me and for my colleagues. Stop a moment to praise colleague Konrad Knell, a San Francisco-based consultant who wrote the definitions below based on several sources, including his work with clients as well as authors such as Collins & Porras (Built to Last and Good to Great), Steven Covey (Principle-Centered Leadership) and Peter Senge (The Fifth Discipline).
Mission: Enduring purpose. The fundamental reason for the organization’s existence beyond just making money. It is a direction, a general heading, a perpetual guiding star on the horizon. It does not change over time. It is generally abstract and can never be achieved, only pursued. For example, for NASA: “advancing man’s capability to explore the heavens.”
Vision: A picture of a desired future that supports the mission. It is a specific destination that is concrete and achievable. A good one engages people—it reaches out and grabs them in the gut. It should be tangible, energizing, highly focused. There can be many visions over time that support the mission. The scale is usually around 1 to 5 years. For example: “a man on the moon by the end of the 60s.”
Strategy: A set of actions or objectives around a unifying theme that work to accomplish a vision. It is broad and action-oriented. If vision is the what, strategy is the how. The time scale of the strategy is equal to or shorter than that of the vision it supports.
Objective: The object of a course of action, something specific that is worked toward. Good objectives should be SMART (Specific, Measurable, Actionable, Realistic, and Time-bound). The time scale is usually less than one year. 
Goal: This term is probably the least consistently used of them all. Usually it is either used interchangeably with objectives or denotes a lower-order or more specific objective. Sometimes it can be on the level of vision, as in BHAG (Big Hairy Audacious Goals).
Values: What’s really important to an organization. They are the essential and enduring tenets—a small set of general guiding principles, not to be compromised for financial gain or short-term expediency. Each value should be a piercing simplicity that provides substantial guidance to the members of the organization. They cannot be copied or dictated; they are what is authentically believed by the leaders of the organization. There should only be a few, between 3 and 6.
Think of Mission-Vision-Objectives as a hierarchy from broadest to most specific. Values underlie them all.
Mission and values are key parts of core ideology. And core ideology is a cornerstone of great companies, organizations, communities. It helps define what a company is passionate about. It aids the selection of who should be on the company bus.
Vision, strategy, objective, goal…key parts of building a visionary organization.
Formulating the vision; figuring the big, hairy, audacious goals; confronting the brutal facts; building a culture of discipline, understanding the technology accelerators can all be attacked through the strategic visioning process.