Comment by nilamo

The typical Office installer is a small bootstrapper that requires an Internet connection to download required files, but applications themselves are native and work offline (some features and applications use web tech for UI, of course).

Subscription-based licensing requires periodic check-ins, but perpetual product key-based licensing is available, though compared to the subscription versions, the release cadence for new features is slow.

The online component of traditional apps like Excel works best as a means for sharing documents, with the web UIs useful for reading and light editing, and the same documents fully editable in the native apps.