Every school has different majors. Professional elective courses are generally supplementary courses for your major starting from sophomore and junior. There may be several courses in a semester. Choose what you like. Usually, the credits for each course are different. The total credits of elective courses selected before graduation should reach a standard, such as 30 points. You can't graduate until you reach it.
Public elective courses are generally for all students, but usually you can't choose your own college courses, which is to cultivate your interest after class. Usually you can take courses such as French, film appreciation, debating art, marketing and self-defense. And you can choose according to the specific courses offered by the school. Usually you can't take more than one or two courses in a semester. The score of each course is two points in our school, and you have to take eight points in four years. I wonder if your school is enough. Generally, the overall requirements will not differ much.