According to the announcement:
WSL 2 uses the latest and greatest in virtualization technology to run its Linux kernel inside of a lightweight utility virtual machine (VM). However, WSL 2 will NOT be a traditional VM experience.
It doesn't exactly clarify how is it different from traditional VM, and how it manages to be faster than WSL (which doesn't not use VM at all). In my general experience, no matter how fast a VM is, it's always slower than native.
Looking for a bit technical answer which can explain how WSL 2 manages to offer better performance than WSL and a Virtual Machine.
