Classes in universities are not necessarily lecture halls, which are generally shared by multiple classes (two or more) of different majors, that is to say, courses are generally large-scale courses or public elective courses.

Stair classrooms are generally large, and full-size classroom teaching is not realistic. Generally, there are not too many stairs on each floor of a teaching building, some are all, but there are not many classrooms on the first floor, and some are equipped with ordinary classrooms, which are generally used for professional classes or class meetings.