Mission statements and vision statements. What are they?

I always have this slight confusion around where to draw the line between mission and vision statements. So, I looked at wikipedia for the exact difference between these two and quite astonished to know how different they are. Excerpt from this article:

Organizations sometimes summarize goals and objectives into a mission statement and / or a vision statement:

• A Definition of Vision in a dictionary: 'An Image of the future we seek to create'.
  A vision statement describes in graphic terms where the goal-setters want to see themselves in the future. It may describe how they see events unfolding over 10 or 20 years if everything goes exactly as hoped.
• A definition of Mission in a dictionary: purpose, reason for being.

Many people mistake vision statement for mission statement. Both are fundamentally different. Mission statement defines the purpose or broader goal for being in the existence or in the business. It serves as a guide in times of uncertainty, vagueness. It is like guiding light. It has no time frame. The mission can remain same for decades if crafted correctly. While vision is more specific in terms of objective and time frame of its achievement. Vision is related to some form of achievement if successful.
For example, "We help transport goods and people efficiently and cost effectively without damaging environment" is a mission statement. Ford's brief but powerful slogan, "Quality is Job 1" could count as a mission statement. While "We will be one among top three transporters of goods and people in North America by 2010" is a vision statement. You can vividly see an image of the organization in year 2010 as one among top 3. It is very concrete and unambiguous goal