Virtualisation in Operating Systems

Virtualisation is the process of creating a virtual version of a physical object.

Virtualisation is of three types primarily: 1. Hardware Virtualisation - Based on simulating real hardware. This can be used to run a complete operating system. This can be further subdivided into full and paravirtualisation.

  1. Desktop Virtualisation - It is the concept of separating the logical desktop from the physical machine.

  2. Operating system level virtualisation (also called as containerisation) - It is the operating system feature in which the kernel allows the existence of multiple isolated user-space instances. Such instances are called containers. Containerisation was introduced as a Linux Kernel feature in 2010. It started gaining momentum with the introduction of Docker.

Hardware Virtualisation

Some terminologies associated with Virtualisation:

  1. Virtual Machine: It is a virtual representation of a physical machine.

  2. Hypervisor: It is a software that manages and monitors running virtual machines.

  3. Host machine: The physical machine that a virtual machine is running on.

  4. Guest machine: The virtual machine running on the host machine.

The following block diagram shows the position of each component mentioned above:

Virtual Machine Diagram


There are two main types of hypervisors:

  1. Native: They run directly on the host machine and share out resources between guest machines.

  2. Hosted: They run as an application inside the operating system and support virtual machines running as individual processes. Eg. VirutalBox,Parallel Desktop

Hypervisor Types

Chaitanya Rahalkar
Graduate Student

Masters in Cybersecurity student at Georgia Tech.