Virtual Machine (VM)
Definition - What does Virtual Machine (VM) mean?
A virtual machine (VM) is a software program or operating system that not only exhibits the behavior of a separate computer, but is also capable of performing tasks such as running applications and programs like a separate computer. A virtual machine, usually known as a guest is created within another computing environment referred as a "host." Multiple virtual machines can exist within a single host at one time.
A virtual machine is also known as a guest.
Techopedia explains Virtual Machine (VM)
Virtual machines are becoming more common with the evolution of virtualization technology. Virtual machines are often created to perform certain tasks that are different than tasks performed in a host environment.
Virtual machines are implemented by software emulation methods or hardware virtualization techniques. Depending on their use and level of correspondence to any physical computer, virtual machines can be divided into two categories:
- System Virtual Machines: A system platform that supports the sharing of the host computer's physical resources between multiple virtual machines, each running with its own copy of the operating system. The virtualization technique is provided by a software layer known as a hypervisor, which can run either on bare hardware or on top of an operating system.
- Process Virtual Machine: Designed to provide a platform-independent programming environment that masks the information of the underlying hardware or operating system and allows program execution to take place in the same way on any given platform.
Some of the advantages of a virtual machine include:
- Allows multiple operating system environments on a single physical computer without any intervention
- Virtual machines are widely available and are easy to manage and maintain.
- Offers application provisioning and disaster recovery options
Some of the drawbacks of virtual machines include:
- They are not as efficient as a physical computer because the hardware resources are distributed in an indirect way.
- Multiple VMs running on a single physical machine can deliver unstable performance