Microsoft will start work proper on the Windows 10 21H1 update – due to land in the first half of 2021 – in June, when testers will begin evaluating preview builds.

21H1 will be the next major update for Windows 10, following the imminent May 2020 Update (20H1), because the next release for 2020, which is of course 20H2, is looking very much like it will only be a service pack-style affair with no major feature additions (as 19H2 was the previous year).

Source Article