"KVM (Kernel Virtual Machine) is a Linux kernel module that allows a user space program to utilize the hardware virtualization features of various processors. Today, it supports recent Intel and AMD processors (x86 and x86_64), PPC 440, PPC 970, S/390, ARM (Cortex A15), and MIPS32 processors.
QEMU can make use of KVM when running a target architecture that is the same as the host architecture. For instance, when running qemu-system-x86 on an x86 compatible processor, you can take advantage of the KVM acceleration - giving you benefit for your host and your guest system." - from wiki.qemu.org
QEMU provides the environment for emulating a computer, such as virtual disks, network interfaces, a video console, etc.
KVM is the software that does the actual magic of virtualization by communicating with CPU
libvirt is the glue that binds it all together. It provides the API to create, destroy, and manage virtual machines.
While CentOS is my preferred server linux distribution, I generally prefer Debian or Ubuntu on the desktop. Most of these procedures apply to both.
sudo yum install kvm virt-manager libvirt virt-install qemu-kvm xauth dejavu-lgc-sans-fonts
sudo apt-get install cpu-checker qemu-kvm libvirt-bin virt-manager
Bridged networking vs Isolated network
Setup a host bridge on your primary interface and copy the IP address from your primary interface to the new bridge interface.
The script create_bridge.sh in this repository will do this for you automatically in CentOS Linux.
If you want your local user to have permissions to create and destroy VMs, add the user to the kvm local group and add the policy kit file (80-libvirt-manage.rules) in this repository to /etc/polkit-1/rules.d/