Definition - What does Hypervisor mean?
A hypervisor is a hardware virtualization technique that allows multiple guest operating systems (OS) to run on a single host system at the same time. The guest OS shares the hardware of the host computer, such that each OS appears to have its own processor, memory and other hardware resources.
A hypervisor is also known as a virtual machine manager (VMM).
Techopedia explains Hypervisor
The term hypervisor was first coined in 1956 by IBM to refer to software programs distributed with IBM RPQ for the IBM 360/65. The hypervisor program installed on the computer allowed the sharing of its memory.
The hypervisor installed on the server hardware controls the guest operating system running on the host machine. Its main job is to cater to the needs of the guest operating system and effectively manage it such that the instances of multiple operating systems do not interrupt one another.
Hypervisors can be divided into two types:
- Type 1: Also known as native or bare-metal hypervisors, these run directly on the host computer’s hardware to control the hardware resources and to manage guest operating systems. Examples of Type 1 hypervisors include VMware ESXi, Citrix XenServer and Microsoft Hyper-V hypervisor.
- Type 2: Also known as hosted hypervisors, these run within a formal operating system environment. In this type, the hypervisor runs as a distinct second layer while the operating system runs as a third layer above the hardware.