Oh no it's 2009 or 20H2 ...
Either way it's still just Windows 10. This week - 20 Oct 2020 - has seen the release of another Windows upgrade.
It's really a bit of a bug-fix and resolves some performance issues. There are a few changes but nothing that should cause any great pains as it really seems to be more of an update to the version earlier in the year. With no major download or install you probably won't even notice it happens!
Usual .....BEST ADVICE is to not go hunting for it - just let Windows do its thing and it should install itself automatically in good time (if it doesn't then you may have other problems).