From my experience, primary schools have head teachers and secondary schools have heads of schools. Also, the head teacher teaches, whereas the head of school does not (like a principal/headmaster). I could be mistaken..
Thank you, it's not a system I am familiar with, so this helps a lot. I have also heard from another commenter that a prefect is a student given some sort of responsibility over other students. I have learned a surprising about about educational systems from this course.