Yeah, so it's Virtual Box using your resources, not Vagrant or Docker. You might want to read up a bit on how containers work -- on a unix system, assuming same

Yeah, so it's Virtual Box using your resources, not Vagrant or Docker. You might want to read up a bit on how containers work -- on a unix system, assuming same cpu architechture (so you don't need a VM) and filesystem that supports overlays, containers have barely any overhead in terms of system resources. You could have a thousand containers running on your machine and be fine. VMs, on the other hand, have pretty serious overhead.