1, full-time: full-time study at school, called full-time. Students attend classes at school all day, focusing on teaching. Different from amateur and correspondence learning.

2. Amateur class: Amateur teaching method generally enrolls students in colleges and universities, which is a form of learning that arranges classes at night or on weekends.

3. Correspondence: Correspondence generally refers to the bad habit of not attending classes at ordinary times and using winter and summer vacations to concentrate on teaching.