W stands for week, and after a few weeks, it will be several W. Weekly class hours refer to the number of hours needed to study the course every week.

Class hours refer to the learning time calculated by class hours. It is generally believed that both non-adult education and full-time university education are 40-minute classes. Therefore, if 30 class hours of training tasks are needed, the effective training time is 30×40= 1200 minutes, 1200/60=20 hours. In addition, we usually don't arrange a break of 10 minutes between classes.