One book, two books and three books are three batches of Chinese college entrance examination, and the main difference lies in the different admission batches. A class of colleges and universities refers to colleges and universities whose college entrance examination scores are in the first batch of admission lines, with high admission batches, such as the domestic 985 project and 2 1 1 project; The second type of colleges and universities refers to colleges and universities whose college entrance examination scores are located in the second batch of admission lines and whose admission batches are low, including provincial undergraduate colleges and ordinary public undergraduate colleges; The three colleges and universities refer to the colleges and universities whose college entrance examination scores are located in the third batch of admission lines, with low admission batches and generally weak comprehensive strength.