Simple meaning of Virtualization and Virtual Machine

Virtualization is an abstraction layer that sits in between the physical hardware and the operating system. Virtualization is a methodology of dividing the resources of a computer into multiple execution environments, by applying one more concepts such as Hardware and Software Partionioning, time-sharing, emulation, simulation and on-demand utilization.

Virtualization allows multiple virtual machines, with different flavours of operating systems like Windows, Linux, Solaris and the respective softwares/applications to run in seperately, just like running multiple physical machines seperately.

What are Virtual Machines ?

Simulation of a Physical Machine in the form of a Software is known as a virtual machine. With the help of virtualization softwares (Hypervisor) the operating system is made to believe that the hardware on which it is running is real and is fully owned by it and no other OS is sharing it, while the Hypervisor provides all the interfacing between the OS and the underlying hardware in a sharing and on-demand mode.

A VM has its own set of virtual hardware (e.g., RAM, CPU, NIC, hard disks, etc.) upon which an operating system is loaded. The operating system sees a normal set of hardware regardless of the actual underlying  physical hardware.
New virtual machines can be created in seconds, without the need of any purchase order and any physical space to worry about. Once a virtual machine is
provisioned, the required OS and softwares can be installed on the VM just like a
physical machine.

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