A virtual machine (VM) is a digital version of a physical computer.
Virtual machine software can run programs and operating systems,
store data, connect to networks, and do other computing functions,
and requires maintenance such as updates and system monitoring.
From:
What is a Virtual Machine?
A hypervisor is computer software or hardware that enables
you to host multiple virtual machines.
From:
Virtualization 101: What is a Hypervisor?
QEMU (home)
VirtualBox (home)