One computer with it's main OS with other operating systems running simultaneously (like a Mac running Windows and Linux)
. All OS's run on the vituralization software
. Manages the virtual platform and it's guest operating systems - the CPU must support it
. Just run the app and not the entire VM - the app contains everything it needs and don't need to launch the whole VM - saves resources
. Provisioning too many systems in the virtual environment, losing track for what they are for
. Virtual system breaks out and interacts with the host operating system or hardware - could control the host or other guest VMs
.