Supervisor vs hypervisor

A hypervisor, also known as a virtual machine monitor (VMM), is software that creates and manages virtual machines (VMs), such as domains in XEN, by distributing resources like memory and processing power across these VMs. While a “supervisor” oversees running processes and controls their access to resources, primarily memory, a “hypervisor” is so named because it supervises the supervisors. In essence, a hypervisor functions as a type of operating system. However, there are key differences: operating systems manage and schedule numerous small processes, while hypervisors manage and schedule fewer but larger virtual machines. Additionally, operating systems handle many small files in complex directory structures, whereas hypervisors manage fewer, larger VM images.