Your browser does not allow storing cookies. We recommend enabling them.


A hypervisor is an operating system instance, or a software package, that creates and manages virtual machines. The hypervisor typically runs on real hardware and allows multiple virtual machines to run on the same hardware. Virtual machines are also called guests.

Virtual machines run guest operating systems. A guest operating system may be different from the host operating system. For example, a Linux computer (hypervisor) may run Microsoft Windows 10 as a guest.

Modern hypervisors in the PC world include VMware ESX, VMware Player, Xen, Citrix XenServer, Microsoft Hyper-V, VirtualBox, and QEMU. VMWare Player, VirtualBox, and QEMU are application-layer hypervisors (essentially like normal programs), though they rely on some specialized operating system support for virtualization. Linux KVM and FreeBSD's bhyve are kernel modules that effectively convert a normal operating system into a hypervisor. In fact, it is often possible to log into a hypervisor (e.g., using SSH keys and use it like a normal operating system.

For more information, see virtualization software.


Highlights from the SSH.COM blog:

  • Cryptomining with the SSH protocol: what big enterprises need to know about it

    Cryptomining malware is primarily thought of as targeting desktops and laptops and is used to hijack system resources to mine cryptocurrency.
    Read more
  • SLAM the door shut on traditional privileged access management

    Did you know that something as trivial-sounding as granting access for your developers or third parties to a product development environment can throw a gorilla-sized monkey wrench into your operations and productivity?
    Read more
  • We broke the IT security perimeter

    Everyone understands the concept of a security perimeter. You only gain access if you are identified and authorized to do so.
    Read more