Microsoft 365 activation is very convenient. KMS can not only activate Microsoft 365 but also Windows series. The ordinary Office 2016 can be purchased once for permanent activation, but the Office 365 version is purchased based on the year. 365 means 365 days, that is, one year, so you need to check the activation time online frequently. If you have not been connected for a long time, you need to connect again to use it.