Here is a list of definitions from the planning process detailed on The Big Picture and The Big Picture Redux.
The Problem: Every nonprofit exists because there is a problem in the world that someone feels needs correcting. Example: People are drowning in a river.

The Need: Needs are root causes of problems. It is best to address the needs to resolve the problem. Example: People fall into the river because there is no guard rail on the bridge.

The Vision: The vision is a description of the world once the problem no longer exists. The vision is stated in the present tense, as though it has already happened. Example: People safely cross the bridge.

The Mission: The mission is simply the commitment to solve the problem and achieve the vision.

Note 1: The Mission and the Vision are why your organization exists. They are why your board exists. They are why donors donate. They are (usually) why volunteers volunteer and staff works. As such, the Mission and Vision should not change. If they do, you should consider creating a new organization.

Strategies: Strategies are broad actions to solve the problem and achieve the vision. Strategies can change if they become ineffective, inefficient, or the environment changes. The number of strategies should be small. They often cover more than one year. Example: Provide warnings (ineffective) or Provide physical protection (effective).

Actions: Actions are the specific steps to accomplish the strategies. You incorporate the actions into the Annual Operating Plan and Budget and manage the actions through those processes. Action plans include What, Who, When, Where, and How much. They often include triggers that start the action and criteria for declaring success. Large action plans should include risk analysis and potential exit gate criteria. Example: The street department will construct guardrails on the bridge in August of next year, with a budget of $100,000.

Values: Values are limitations on strategies and actions that are important to the organization. Example: We will not violate the state standards for bridge construction or We will not borrow money to pay for bridge improvements.

Note 2: The Mission and Vision should not have words of Strategies, Actions, or Values, as these can change over time. The words “by”, “via”, or “through” imply strategies.

Note: 3: Objectives and Goals are often confused. In fact, the definitions seem to swap about every 7 years. Currently, objectives are broad and goals are specific and quantitative. The Vision defined above is really an objective and the Action Plans are goals.