Even though I have already known the Microsoft office online version for long. I have never tried it until just now. I find it easy to use and handy. Most importantly, apart from saving the file on the OneDrive; the files can also be downloaded to the PC. I believe this is a new feature implemented by Microsoft recently.
Attached are some screen shots for your viewing.
1) All apps gathered in a single window
2) Word online
3) Powerpoint Online
4) Excel Online
5) Saved files on the PC, can be open by Microsoft Office
With OneDrive you can share the files with colleagues, co-workers, family members and friends. I can find the reason for buying expensive PC version M$ office!!!