You spend 12 to 16 hours each week in class. The academic year is divided into two separate 15-week semesters, plus a week after each semester for exams. Most of your classes are arranged for you. You arrange your own schedule in consultation with your academic adviser. Schedules tend to look lighter than they really are.
Teachers carefully monitor class attendance.
Professors may not formally take roll, but they are still likely to know whether or not you attended. Classes generally have no more than 35 students. Classes may number 100 students or more. You are provided with textbooks at little or no expense. You are not responsible for knowing what it takes to graduate.