Source: Windows Central
Microsoft has just unleashed the Windows 10 May 2021 Update (version 21H1), and it is slowly making its way to compatible devices. This is the refresh number eleven after the original release, and it only includes a small set of improvements and several fixes to complement the work done with the May 2020 Update (version 2004) and October 2020 Update (version 20H2).
If you have a device running the October 2020 Update or May 2020 Update, then version 21H1 is available as an optional update through the Windows Update settings. This means quick installation like a cumulative update without a complete upgrade since the device only needs an enablement package to switch versions.