It's a school or a prison?

For some time I've been thinking about this issue, in how the school it's looks like a prison.
There are many similarities: The school and the prison have a management team that regulates the internal order and the coexistence, and that in many cases they decide the way to follow in both institutions. Both institutions have walls or fences of a considerable height, entrance and exit gates, cells in one case and classrooms in the other, but that in the end are very similar, since they are usually closed. Both have a yard where you walk at determined times, you talk, you do some sport ... but alone, at determined times, when the decided time arrives. Both have dining services and extracurricular activities with which they spend time.
It is coincidence?