OneDrive for Business has come a long way since its SkyDrive days, and the modern sync client is better than ever with improved features and a more efficient user experience. This article explains how the OneDrive Sync Client works and some of the ways it does more than just make personal files available across devices, such as how it supports connecting to Microsoft Teams and SharePoint Online.
Microsoft has released a preview of co-authoring for protected (encrypted) Office documents using the desktop apps. While it might seem straightforward to enable co-authoring (and the online apps have been able to do this for over a year), making it work for the Office desktop apps requires a complex mix of Office, SharePoint Online, the OneDrive sync client, and sensitivity labels. Once everything lines up, it works beautifully, even if you can't take a screenshot to prove that it works.