https://blog.faceutil.com/2017/04/21/microsoft-cloud-os-%eb%a7%8c%ed%99%94-%eb%a7%88%ec%9d%b4%ed%81%ac%eb%a1%9c%ec%86%8c%ed%94%84%ed%8a%b8-%ed%81%b4%eb%9d%bc%ec%9a%b0%eb%93%9c-os-%d1%8f/