Booking a class is to reserve a class after you finish the courseware. That is to say, after you finish learning a unit, go to the class schedule to find the course of the unit you just learned, and then the teacher will explain it. It's called a lesson.

Student handbook

The student handbook is the book where you set the course. And every time you finish a small class, the teacher's comments will be on it.

Salon class

Salon classes can be arranged at any time on the schedule. Booking a class is to see that there are classes you need to attend on the schedule, write down the time and tell the front desk, and the front desk will book you the courses you need. The number of people in the salon is also controlled, because the quality of study should be guaranteed.