Despite the confusion with the payment model between Microsoft Office (one time payment) and Microsoft Office 365 (subscription). There is the issue between the different installation versions. You can install it either as an "app" or as as a "desktop application". The current tags don't differentiate but the two version are technically different.
As far as I understand, the app version only works with an office 365 subscription (I'm not completely sure though). However with the 365 subscription you also have the possibility to install a desktop application and it will "overwrite" the app (just tested that).
What would be good tags to differentiate between the "desktop version" and the "app version"?