When you graduate from high school, you're emancipated from the confines of school. Emancipated means "free from restraints."
When someone is set free from traditional restrictions, the kinds of limitations that society puts on a person, that person can be described as emancipated. A classic example of this is a woman who has escaped societal expectations of what women should do to live the life she chooses, or a member of a minority group who has become emancipated to achieve equality within his society. Emancipated can also describe a person who has turned 18 and is no longer a minor — old enough to be treated as an adult and not legally controlled by his or her parents.