SAT Scholastic Aptitude Test. It is a set of standardized tests that many colleges and universities in the USA require for admission. It doesn't influence one's grades. Most universities have admissions standards that include some combination of SAT scores and grade point averages (GPA). The higher one's SAT scores, the lower the GPA need be to be considered. The lower the SAT, the higher the GPA must be. There are several parts to the SAT (reading, maths, etc.) and the student can sit the SAT as many times as they wish (and can afford.) My son is considering attending uni in the USA, so he must take the SAT. He is in year 12, which is the same as a high school junior in the USA. He can sit the SAT again next year if he wishes. It depends on his scores this time if he will do it or not.