Why do a lot of these providers differentiate between OpenVZ and KVM? Usually there's a significant pricing difference, but little in the way of explanation as to why.
KVM is stronger isolation, its a hardware layer virtualization. You can (though the provider might not let you) run a custom kernel, etc.
OpenVZ is more OS virtualization, there is less isolation between instances.
OpenVZ usually has "guaranteed CPU/RAM" and "burst CPU/RAM", while KVM always gives you what its assigned. The guaranteed/burst is typically BS. More often these budget providers like OpenVZ because you get greater density, which means more noisy neighbor and taxed resources like disk IO.
OpenVZ is more OS virtualization, there is less isolation between instances.
OpenVZ usually has "guaranteed CPU/RAM" and "burst CPU/RAM", while KVM always gives you what its assigned. The guaranteed/burst is typically BS. More often these budget providers like OpenVZ because you get greater density, which means more noisy neighbor and taxed resources like disk IO.