My understanding of WSL is that Linux software runs natively on Windows by virtue of a compatibility layer. Eg. if there is a fork() in my code it will be translated into CreateProcess() or something like that.
https://blogs.msdn.microsoft.com/wsl/2016/04/22/windows-subs...
About 10/15 years ago I used andLinux to have a Linux shell and other apps inside Windows. It was really good and it seems ahead of its time, as it was not virtualized.