Hypervisor

What is a Hypervisor?

A hypervisor is control software that enables the virtualization of a computer, allowing multiple virtual computers to run on a single physical server. These virtual computers operating within a virtual environment are referred to as "virtual machines."

There are two main types of virtualization methods:

1. Host-based Virtualization:
   In this method, virtualization software runs on top of an operating system (host OS), and virtual machines (guest OS) operate on top of that. This approach allows for the easy setup of virtualization environments, similar to running an application, and enables the host OS and guest OS to be displayed on the same screen. However, this method consumes resources for the host OS, which is not always optimized for virtualization, making it less ideal for running multiple virtual machines on a single physical server. It is typically used for scenarios such as running Windows on macOS for cross-platform functionalities.
2. Hypervisor-based Virtualization:
   With this method, the hypervisor runs directly on the hardware, and virtual machines operate on top of it. This approach is better optimized for virtualization, making it more suitable for running numerous virtual machines on a single physical server. It is widely used for server virtualization and is also common in Virtual Desktop Infrastructure (VDI), where desktop environments are virtualized and run on servers, with only the screen output delivered to client terminals.

Popular hypervisors include VMware's vSphere ESXi, Citrix's XenServer, Microsoft's Hyper-V, and the Linux-based Kernel-based Virtual Machine (KVM).