A hypervisor or virtual machine monitor (VMM) is computer software, firmware, or hardware, that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called a host machine, and each virtual machine is called a guest machine. The hypervisor presents the guest operating systems with a virtual operating platform and manages the execution of the guest operating systems.
Definition of REGRESS. 1. a: an act or the privilege of going or coming back b: reentry 1. 2. : movement backward to a previous and especially worse or more primitive state or condition. 3. : the act of reasoning backward.
As you might guess, regress is the opposite of progress. So if a disease regresses, that's generally a good thing, but in most other ways we prefer not to regress. If someone's mental state has been improving, we hope he or she won't start to regress; and when a nation's promising educational system begins to regress, that's a bad sign for the country's future.