In this blog, we describe the products Microsoft 365 and Microsoft Office 2021, their differences, and their similarities. And which one should you go for? In this blog, we describe the products Microsoft 365 and Microsoft Office 2021, their differences, and their similarities. And which one should you go for? If you are new to the suite of apps or Microsoft Office, you'll find two products, including Microsoft Office 2021 and Microsoft 365, making the decision a little more complicated. Although these offers give you access to similar apps, the difference comes down to the list of benefits and prices. Microsoft Office 2021 is a standalone version of the apps that you can own forever after a one-time purchase. The standalone version of Office (also called the "permanent" or "on-premises" version) will allow you to install and update apps on a single computer. You can't upgrade to the next version.