Class hours: refers to how many class hours are required for this course. For example, a course lasts 50 hours a semester, and it usually takes nearly two hours to learn a large class. That is to say, this course has 25 classes from beginning to end. Extended information credits: There will be an exam at the end of each course, usually with scores. If you pass, you will get credit for this course. Credits will only be reflected in the' reward' for next semester. There are still some credits that need to be taken. For example, the school requires that the four-year elective credits of the university must reach 4 points. Most elective courses are 1 credit, and there are also 2 credits. In other words, you must take at least two courses in four years.