When this specific build was active in 2019, Microsoft had fully transitioned to its "Servicing Channels" model for Office 365. This specific release belongs to the , later simply called the Semi-Annual Enterprise Channel.
: In modern versions of Windows, you can simply right-click the .iso file and select "Mount" to access the internal setup files.
Because this is a Volume License ISO (not Retail), you must activate via a Key Management Service (KMS) host or a Multiple Activation Key (MAK).
A "distraction-free" mode that hides all ribbons and UI elements, leaving only your document on a dark background—ideal for deep writing sessions.
Understanding this specific ISO requires deconstructing the naming convention used by Microsoft for its installation media:

