This means you own the copy forever after the one-time purchase. Microsoft Office 2019 is the name for the standalone version of the product, and it's the offering that does not require a subscription.
Although these offerings give you access to the same set of apps, the difference comes down to the list of additional benefits and costs. If you are new to Microsoft Office or plan to upgrade the suite of apps, you will come across two products, including Office 2019 and the Office apps from Microsoft 365, making the decision a little more difficult.
