I think you misunderstand the meaning of the word "수강".
"수강" means the selecting the class out of the various classess, which you want to sign up for.
In other words, "수강 시스템" means the Computer website program helping you select the class next semester.
As you know, All the class has the limitatnon on it's number of student. So, most students try to access to the website system competitvely. There are a lot of competition.