Hypervisors

A hypervisor, also known as a virtual machine monitor (VMM), is the software that creates, runs, and manages virtual machines (VMs). It's the essential component that enables virtualization by abstracting the underlying physical hardware from the operating systems and applications running on top of it. There are two main types of hypervisors. 'Type 1', or 'bare-metal' hypervisors, run directly on the host's hardware to control the hardware and to manage guest operating systems. For this reason, they are sometimes called native hypervisors. Examples include VMware ESXi, Microsoft Hyper-V, and open-source options like KVM. Because they have direct access to the physical hardware, Type 1 hypervisors are highly efficient and are the standard for enterprise data centers and public cloud providers. 'Type 2', or 'hosted' hypervisors, run on a conventional operating system (OS) just like any other software application. A guest OS runs as a process on the host. This type is often used for desktop virtualization, allowing users to run different operating systems on their personal computers. Examples include VMware Workstation, Oracle VirtualBox, and Parallels Desktop. While they are easier to set up, they introduce more overhead and have lower performance compared to Type 1 hypervisors because they have to go through the host OS to access hardware resources.