en.wikipedia[.]org/wiki/Windows_Subsystem_for_Linux
Linux in Windows has improved quite a bit with v. 2, and will only get better with new releases of Win10. Unfortunately Microsoft uses its Hyper V to make it all possible. So not only is the installation of WSL 2 a bit of a hassle -- install v. 1 first, then add updates, then install Linux, then update Linux etc... -- but as with anything Hyper V, it leaves VirtualBox users out in the cold.
If you Google long enough you will come across a very few references to using V/Box when Hyper V is enabled. It is [in theory at least] possible if/when you enable/install the Virtual Machine Platform, which is an added feature like WSL. At the least V/Box VMs will be slower, if your existing VMs will run at all -- my frequently used Win7 32 bit VM will not. I have an additional copy of Win10 with Hyper V enabled, but quite a few [most?] people in this boat create another boot menu entry for their single copy of Win10 using EasyBCD, using the BCD option turning off Hyper V for their 2nd entry.