Credit mean what?

Hello , i am a international student , now i study in high school , i see the GPA is very important in CC, because have high GPA and SAT, it can help to transfer a better university, i know how to calculate GPA, but i don’t understand what is credit mean? can anyone help me ?

Each class is worth a certain amount of “credit hours.” This may differ by university. At mine, most classes are worth 3 credits, and some math and science classes are worth 4. Credit makes some classes worth more in GPA calculation. If you get a C in a 5 credit class, that “counts” more heavily against you than a C in a 2 credit class would.

Credits are sometimes called ‘hours’ or credit hours or units if that is more familiar to you.

It wouldn’t be unusual for a foreign high school not to assign a credit value to classes. If all of your grades count the same towards your GPA, they would all carry the same credit value. In this case, you may report “1 credit” for each class on your school report.

Things can be complicated if the HS has early concentration in subjects. In the US, each HS subject usually requires the same number of class hours (five 50-minute periods) per week. But an international HS may have 3 concentrations: a) math concentration, b) natural science concentration, and c) humanities concentration. A math class may require 8 class hours per week for math concentration but only 1 class hour per week for humanities concentration. This was the situation in my former country. On my transcipt, each class had different credit weight (coefficient from 1 to 5) for GPA calculation.