Below is a brief summary of all the changes to Windows 10 in the "May 2021 Update" version 21H1 which was released on the 18th May 2021.
This is a very minor update so not many changes to cover, and most of those are related to enterprise customers anyway.
Like previous major updates to Windows 10 it will be released in waves so not everyone will receive it at the same time, so it may be several weeks/months before your computer automatically updates to this new edition.
N.B. For the first few weeks it will appear as an 'optional' update which you can choose to install via Windows Settings, after a period of testing it will then start to install automatically on all devices.
If you are offered this new version in the first few weeks of release then my advice would be to postpone it for a while to allow for any initial problems to be resolved before you go ahead and upgrade, as with previous releases there were quite a few initial teething issues which caused some major problems to customers who had chosen to upgrade immediately. I will update this page and/or my news page when I am happy it is safe to install.
Because this is such a minor update then for computers which are already reasonably up-to-date e.g. running version 2004 or 20H2 then the upgrade process to 21H1 will be very quick as it will install in the background just like any other security patch / update.