The semester system in the United States, like that in China, takes the autumn semester as the beginning of a school year, and it is also the main semester for freshmen to enter the exam and enter the school. The semester system of American undergraduate courses can be divided into the following three types:

Term (term system):

The most common. This semester system divides a school year into two main semesters: autumn semester and spring semester, each semester is about 16 weeks, plus summer semester (usually lasting 4-6 weeks), which constitutes a complete school year. Some schools divide the summer term into two parts, Summer I and Summer II. This semester system is also called "4- 1- 1-4" semester system. In short, the semester system is characterized by only two main semesters in a school year: the autumn semester and the spring semester, and the status of the summer semester cannot exist beyond that of the main semester. Among them, you need to register in the autumn semester and the spring semester (registration means paying tuition fees), and you don't need to register or report in the summer semester. Typical school representatives: 7 Ivy League schools except Dartmouth College.

Three semesters (three semesters):

This semester system divides a school year into three semesters: autumn semester, spring semester and summer semester, and each semester lasts 15- 16 weeks. Under this semester system, the summer semester has also gained the status of the main semester. The only difference is that if you don't register for the summer semester, you don't need to report to the school-you have to report to the other two semesters. Representative of typical school: University of Michigan at ann arbor.

Quarter (school season):

This semester system divides a year into four semesters: autumn semester, winter semester, spring semester and summer semester. Each semester lasts 10- 12 weeks, and the summer semester is slightly shorter, usually 8- 10 weeks. Each student should study for at least three semesters each academic year. You don't need to register with the school in summer, but you need to register in other semesters. Typical school representatives: 10 University of California System, Stanford University, Dartmouth College, University of Chicago.