Broadly speaking WSL1 is linux implemented in the windows kernel, think reverse wine. WSL2 is linux running on a thin VM with several bridge layers that can access windows resources (networking, files, GPU, etc.)
Thanks for the explanation! I always knew that WSL1 was implemented on the Windows kernel and thought it was quite ambitious - props to them! I didn't know they moved to the VM model for WSL2.
Isn't WSL1 everything _but_ linux? I.e. more like gnu/WinNT.