The main difference between Microsoft 365 and Office 2021 Professional lies in the purchase method and the offered features. Microsoft 365 is a subscription service that is continuously updated with the latest features along with extra benefits such as substantial OneDrive storage.

Office 2021 Professional, on the other hand, is a one-time purchase that gives users access to the classic Office applications with all security and application updates. You can save a lot of money on subscriptions. You will not have extra OneDrive storage, but there are alternatives.

Yes, Office 2021 Professional provides support for both 32-bit and 64-bit versions on Windows, while the Mac version supports only 64-bit. This ensures that users can choose the version that best fits their system architecture

Although Office 2021 Professional can be used offline for most features, internet access is required for activation, receiving updates, and using certain features such as online storage services. Regular internet connection also helps ensure activation status and receive important security updates

Office 2021 introduces several new features and improvements, such as XLOOKUP and Dynamic Arrays in Excel, a dark mode in Word, and enhanced capabilities for slideshow recordings in PowerPoint. These updates improve the user experience and provide advanced tools for data analysis and presentation​

For Windows users, Office 2021 Professional Windows 10 home or Windows 10 Pro or Windows 11 Home or Windows 11 Pro  or later. This ensures that the software performs optimally on systems that are up-to-date with the latest operating system innovations from Microsoft

For installing Office 2021 on a Mac, it is important to first check whether your device meets the system requirements. Apple only allows the installation of Office on the latest three versions of macOS. 

A license for Office 2021 Professional allows 1 installation on één single device. The version for 5 allows you to install on 5 devices. Office 2021 Professional plus with account allows you to install on 1 device and you can reinstall unlimitedly on the same or a new/other device. This underscores the importance of choosing the right device for your installation

Depending on the subscription, includes Office 2021  desktop versions of Outlook, Word, Excel, PowerPoint, OneNote, Access (PC only) and Publisher (PC only). It also includes Office 2021 the integration with MS Teams.