Bringing Office to the browser “Web Apps” is the official branding for the online versions of the Office suite, and the name fits.

Previously, those apps launched into an Edge tab, but the update to Edge now caused them to launch as Progressive Web Apps (PWA), which loads them in their own windows with a minimal UI.

Microsoft is refreshing the UI of its Office suite of apps, bringing them in line with Windows 11. These are rolling out to Windows 10 and Windows 11 users running Beta Channel Office Insider builds.

The UI Fabric is Microsoft's set of tools for developers using the React JavaScript library to build user interfaces for web apps. SEE: 20 pro tips to make Windows 10 work the way you want (free PDF) ...