A vision is when you experience a specific possibility as a potential for yourself. It has to have the element of it being possible for you. 

It may come in the form of an idea, a dream, or a realization such as an "aha experience." Vision is direct communication from Life itself. 

In addition to serving you personally, vision is critically important to the culture that you are a part of. It was standard practice in many Native American and aboriginal cultures to receive and share one's vision to make the people stronger.

Benefiting the community was the primary intention for doing vision quest and other ceremonies intended to receive a vision. 

In this sense, vision is receiving collective guidance for the people that you are a part of. This has been the role of the Shaman and spiritual leaders in cultures all over the world for thousands of years.

In Black Elk Speaks (Neihardt, 1961, p.188), Black Elk states "When a vision comes ... the world is greener and happier; for wherever the truth of vision comes upon the world, it is like a rain." 

When referring to myth-makers such as shamans and artists in his book, The Power of Myth (1988, p.85), Joseph Campbell states:

"They (ideas and poetry) come out of an elite experience, the experience of people particularly gifted, whose ears are open to the song of the universe. These people speak to the folk, and there is an answer from the folk, which is received as an interaction. But the first impulse of shaping of a folk tradition comes from above, not below."  

Receiving a vision benefits everyone involved. You receive direction and value at a personal level, and your community and culture also receive guidance and richness.

As Campbell pointed out, culture and tradition itself come from such experiences. Vision is the life-blood of culture, tradition, and ceremony.

Without the input of vision, tradition becomes outmoded and meaningless. A once vibrant ceremony or tradition soon becomes rote and detached from Life in the absence of current vision.