You can block access for applications that do not use the modern authentication libraries to connect to SharePoint Online. This includes Office 2010-based applications, as well as the legacy OneDrive for Business (Groove) client and most third-party clients.

The available settings are as follows:

• Allow access
• Block access

If you configure unmanaged device restrictions to Allow limited, web-only access or Block access, the Block access option on this page is automatically selected.

Now that we have learned how to manage our different security options, we'll learn how to assign guest licenses.