https://blog.gongquiz.com/2021/03/31/%eb%86%80%ec%9d%b4%eb%b0%a9%eb%a7%a4%ed%8a%b8pvc-vs-%ed%8f%b4%eb%8d%94%eb%a7%a4%ed%8a%b8pe-%ec%96%b4%eb%96%a4%ec%b0%a8%ec%9d%b4%ea%b0%80-%ec%9e%88%eb%82%98-%e2%84%83/