Lines A and B of college admission scores are batch numbers, which refer to the batch order of admission. The more important the university, the higher the admission batch. The first batch are key universities, undergraduate courses; The second batch is ordinary universities, undergraduate courses; The third batch of A lines are ordinary colleges and universities, public; Line B is a general college, a higher vocational college, and a junior college, which is basically a private school.

Universities all over Chinese mainland have AB lines. A line usually represents public schools, with reasonable tuition fees, but high admission scores; Line B usually represents private schools with higher tuition fees but lower admission scores. However, in the same university, the academic qualifications of A-line and B-line students are recognized and consistent by the state, and there is no difference in diplomas.