What Is a Virtual Machine?

Many people use VMs everyday to access computers in another location

A virtual machine uses software and computer hardware to emulate additional computers in one physical device. Learn more about what a virtual machine is and what you can do in a VM environment.

What Is a Virtual Machine?

Virtual machines emulate a separate operating system (the guest) and a separate computer from your existing OS (the host), for example, to run Unbuntu Linux on Windows 10. The virtual computer environment appears in a separate window and is typically isolated as a standalone environment. Still, interactivity between the guest and host is often permitted for tasks such as file transfers.

Virtual Machine of Apple computer running Windows


Everyday Reasons for Using a VM

Developers use virtual machine software to create and test software on various platforms without using a second device. You can use a VM environment to access applications that are part of an operating system that's different from the one installed on your computer. For example, virtual machines make it possible to play a game exclusive to Windows on a Mac.

In addition, VMs provide a level of flexibility in terms of experimenting that is not always feasible on your host operating system. Most VM software allows you to take snapshots of the guest OS, which you can revert to if something goes wrong such as a malware infection.

Why Businesses Might Use Virtual Machines

Many organizations deploy and maintain several virtual machines. Rather than running several computers at all times, companies use VMs that are hosted on a smaller subset of powerful servers, saving money on physical space, electricity, and maintenance.

These VMs can be controlled from a single administrative interface and made accessible to employees from their remote workstations, often spread across multiple geographical locations. Because of the isolated nature of the virtual machine instances, companies can allow users to access their corporate networks using this technology on their computers for added flexibility and cost savings.

Virtual machines give admins full control along with real-time monitoring capability and advanced security oversight. Each VM can be controlled, started, and stopped instantly with a mouse click or command line entry.

Common Limitations of Virtual Machines

While VMs are useful, there are notable limitations that need to be understood so that your performance expectations are realistic. Even if the device hosting the VM contains powerful hardware, the virtual instance may run slower than it would on its independent computer. Advancements in hardware support within VMs have come a long way in recent years. Still, this limitation will never be completely eliminated.

Another limitation is cost. Aside from the fees associated with some virtual machine software, installing and running an operating system may require a license or other authentication method. For example, running a guest instance of Windows 10 requires a valid license key just as it does when you install the operating system on an actual PC. While a virtual solution is typically cheaper in most cases than purchasing additional physical machines, the costs add up if you require a large-scale rollout.

Other potential limitations to consider are the lack of support for certain hardware components and possible network constraints. As long as you do your research and have realistic expectations, implementing virtual machines in your home or business environment could be beneficial.

Hypervisors and Other Virtual Machine Software

Application-based VM software, commonly known as hypervisors, come in all shapes and sizes tailored toward personal and business use. Hypervisors allow multiple VMs running different operating systems to share the same hardware resources. System administrators can use hypervisors to monitor and manage multiple virtual machines across a network all at once.

  • What do virtual machines have to do with operating systems?

    Once you have a virtual machine application installed, you will need to choose and install an operating system on your virtual machine. Once an OS is installed, you can use your virtual machine like any other computer.

  • What's the difference between an emulator and a virtual machine?

    Virtual machines are fully-featured, standalone environments where you can install and use entire operating systems. Emulators seek to recreate specific software and hardware virtually to accomplish a particular goal, like playing a game on an out-of-date system.

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