Under , look for "Click-to-Run" next to the version number. If it isn't listed, you likely have a legacy MSI-based installation. Office C2R Installers | MAS - Microsoft Activation Scripts
The only minor downside is that C2R isn’t ideal for very locked-down or offline environments, but for most business or personal setups, it’s perfectly fine. If you need predictable, up-to-date Office installations with minimal hassle, C2R is the way to go.
For a long time, there were two ways to get Office:
C2R allows organizations and individuals to control the frequency of updates through various "channels":
: Because it uses virtualization, C2R allows multiple versions of Office to coexist on the same machine more easily than the legacy MSI-based versions. How C2R Update Channels Work
: Users can begin using Office applications while the installation continues in the background.