Microsoft's OneDrive is now a progressive web app (PWA). The move allows the website to feel a bit more like a native app. It can now be "installed" through Microsoft Edge to open in its own window. The OneDrive PWA can also be set to launch automatically when a PC is turned on. People can also pin the PWA to their Start menu or Taskbar on Windows.
Just like the OneDrive website, the PWA doesn't replace the OneDrive sync client. If a person wants OneDrive files to appear and sync through the File Explorer, they'll have to use the OneDrive sync client that ships with Windows 10.
Microsoft also has a OneDrive app in the Microsoft Store that provides much of the same functionality as the OneDrive progressive web app.
Interestingly, Gustafson discusses an upcoming Filesystem Access API. This could be used to allow the OneDrive PWA to sync files on PCs, but the team behind OneDrive may not choose to use it.
The Filesystem Access API is coming… not saying they'd use it, but this would be a use case for it. And last time I was paying attention to that conversation, I think they were looking at PWAs being granted the permission (by users) for longer than browser tabs.