PSAT stands for Preliminary SAT. The full name is actually PSAT/NMSQT because not only does the test help you understand how you might perform on the SAT or ACT, it is also used to help qualify students as National Merit Scholars as well as identify individuals who will receive merit scholarships.
Students typically take the test in their junior year of high school. While the national average PSAT score is around 980, those wanting to be considered for a National Merit Scholarship will need to earn more than 1400 points, depending on your state of residence.