https://genesis-aka.net/language/japanese/2021/08/23/%e4%b8%8d%e5%8b%95%e7%94%a3%e6%a5%ad%e5%8b%99%e6%94%af%e6%8f%b4saas%e3%80%8c%e3%81%84%e3%81%88%e3%82%89%e3%81%b6cloud%e3%80%8d%e3%81%a71%e5%8c%ba%e7%94%bb%e5%86%85%e3%81%ae%e8%a4%87%e6%95%b0%e7%89%a9/