For those of you who have never heard of this, it's macos's LVM. Why they didn't just refer to it as LVM is beyond me.
It doesn't really do everything that a real LVM does though. This was used to support those annoyingly bad Fusion Drives. They dropped them around 2020 I think.
> Why they didn't just refer to it as LVM is beyond me.
Because it isn't LVM, and giving it the same name as another similar-but-distinct technology would just make matters more confusing.