For students who will be studying in China over 180 days (starting from the date stated in the Admission Notice), you will be issued X1 visa. The validity of X1 visa is 30 days and students will be required to apply for a Residence Permit through the school within 30 days of arrival in the country.
For students who will be studying in China less than 180 days, you will be issued X2 visa. The validity of the X2 visa is between 30-180 days, and is usually only for a single entry. Once you have exited the country, you will not be able to enter the country again with the previous visa.