Microsoft has just begun to roll out the feature update for Windows 10 with the version number 1903. The list of changes is quite long and includes the "reserved storage" feature, a new light desktop theme option, Windows Sandbox (it does exactly what the name says), the long-awaited unified Search box, and much more.
https://www.notebookcheck.net/Windows-10-May-update-version-1903-rolls-out.421288.0.html