3a and 3b are not undergraduate courses, but junior colleges. 2a is the second batch of A-line, 2b is the second batch of B-line, 3a is the third batch of A-line and 3b is the third batch of B-line. 3a institutions in the third batch are public institutions, while 3b institutions in the third file are mainly private institutions. Extended information undergraduate course refers to the basic component of higher education, which is generally carried out by universities or colleges, and very few higher vocational colleges have carried out applied undergraduate education. Undergraduate education is more important than general education of theoretical majors, and applied undergraduate education is more important than applied professional education and practical skills education. Students can generally get undergraduate diploma and bachelor's degree certificate after normal graduation. In China, undergraduate education is mainly divided into full-time undergraduate education and part-time undergraduate education.