Why is part of Zhihu's answer folded? What does folding have to do with "not helping"?

What is "folding" Zhihu's original intention is to help people better share each other's knowledge, experience and views. In Zhihu, we encourage users to create valuable content. Folding function is a mechanism introduced by Zhihu in order to maintain a good question-and-answer discussion atmosphere. If the content is not helpful to answer the question, it will enter the collapsed area and be displayed at the bottom of the answer list.