High school is mandatory and usually free.
Your time is structured by others.
You need permission to participate in extracurricular activities
You can count on parents and teachers to remind you of your responsibilities and to guide you in setting priorities.
You are not responsible for knowing what it takes to graduate.
The school year is 36 weeks long; some classes extend over both semesters and some don't.
Going to high school classes
You seldom need to read anything more than once, and sometimes listening in class is enough.
You are expected to read short assignments that are then discussed, and often re-taught, in class.
Lecturers may not always check completed homework, but they will assume you can perform the same tasks on tests.
Teachers remind you of your incomplete work.