Differences between Microsoft Office and Microsoft 365?

the App Store apps will require you to subscribe to Microsoft 365. Buy from Microsoft:

Office for Mac running macOS Catalina

If you have Office 2011 for Mac or before WILL NOT run.

Office 2016 for Mac needs to be v15.35 or later.

Update the software

https://docs.microsoft.com/en-us/officeupdates/update-history-office-for-mac


The current Office for Mac; Office 365 or Office 2019 (One-time purchase) are OK with Catalina

How do I upgrade Office?

https://support.office.com/en-us/article/how-do-i-upgrade-office-ee68f6cf-422f-464a-82ec-385f65391350

compare:

https://products.office.com/en-us/compare-all-microsoft-office-products?&activetab=tab:primaryr1

Office Home & Student 2019:

https://www.microsoft.com/en-us/microsoft-365/p/office-home-student-2019/cfq7ttc0k7c8?activetab=pivot:overviewtab

Office Home & Business 2019: This stand alone includes Outlook—

https://www.microsoft.com/en-us/microsoft-365/p/office-home-business-2019/cfq7ttc0k7cq?activetab=pivot:overviewtab