How MS Office is paid for
Of the differences between Office 2019 and Office 365, purchase plans are among the most striking.
Office 2019, whether bought one copy at a time in retail or in lots of hundreds via volume licensing, has been dubbed a "one-time purchase" by Microsoft to spell out how it"s paid for. (Labels like "perpetual," which have been widely used by Computerworld, technically note the type of license rather than payment methodology, but in Office"s case, the kind of license is tied to whether it was bought outright or simply "rented.")
Microsoft defines the term as when "...you pay a single, up-front cost to get Office applications for one computer." Up-front is the key adjective there; Office 2019"s entire purchase price must be laid out before receiving the software.
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That purchase, actually of a license to legally run the software, gives the buyer the right to use Office 2019 in perpetuity. In other words, the license has no expiration date, and users may run the suite as long as they want. Pay for Office 2019 this year and use it for the next seven years? Fine. Run it until 2030? Nothing to stop you.