What is the central idea of this passage?

The debate has been around for a long time. Depending on whom you ask, homework is either the most important teaching tool, or it's just meaningless work. But the truth is that homework has some benefits. First, homework helps students go over what they learned in a calm and peaceful environment. This review helps them pinpoint their strong and weak points. It also helps them practice the concepts they learned in school. As a result, students are better prepared to understand the teacher in class.