What is the meaning of "Banner enrollment"?

Question

In a sentence like the following, what does "Banner enrollment" mean?

For the first 3 weeks of the semester, students are added automatically by the Banner enrollment, after the 3rd week of classes this will stop and then you can remove students who have dropped the course.

Answer 1

Many universities use a computer system called BannerWeb for students to register for classes.

The sentence you quote is directed toward professors, and means that students who wish to add a class can still do so for three weeks after the semester begins. They can do this on their own, using the BannerWeb system. After the third week, professors can then access (through BannerWeb) the final class rosters, and remove students' names from the rosters (drop them from the class) if they have not attended classes, or have otherwise communicated to the professor that they wish to drop the class.