Good read to understand relation of Virtualization - Hypervisor - KVM -QEMU

- KVM is linux kernel modul. No gui. Only provide CPU and RAM, not hd, network etc.

- Qemu is an emulator of varied cpu. It also has features to use KVM which will boost performance compare to other emulated cpu type.

-Libvirt as wrapper to start QEMU with the right options.

For more, refer this good explanation:

 https://superuser.com/questions/1490188/what-is-the-difference-and-relationship-between-kvm-virt-manager-qemu-and-libv