A vision quest is a rite of passage. As such, it tends to involve being separated from one's community, being tested, and then returning to the community.
In a vision quest, a young person typically is secluded from society. This often takes the form of going out into the wilderness alone. The person is typically tested by being put through an ordeal. They typically fast for a number of days while alone in the wilderness. During this time, they hope to receive a vision from some sort of spirit. The spirit will give them guidance about how to live their lives. Once this has occurred, the young person returns to society.