GPA is a number that shows how well a student has done, on average, over a term, a year, or a whole degree. The letters stand for grade point average. In the US system each mark (A, B, C…) is turned into points — often 4.0 for an A, 3.0 for a B, and so on — and those points are averaged, usually with more weight for classes that carry more credits. So it is not one test score; it is a running average of many classes. US high schools and universities put it on transcripts; scholarships and later-school applications often ask for it. Though actually, not every school uses the same scale: some use plus and minus (A-, B+), which changes the points a little, and a 4.0 GPA is not the same kind of number as a Taiwanese 百分制 average. In student chat the letters GPA are completely normal; on forms they are formal enough to stand alone. Taiwanese university students say GPA a lot too, especially when they talk about going abroad, even when the school also prints a percentage average.