What Is a Virtual Machine?

Many people use VMs everyday to access computers in another location

A virtual machine uses a combination of software and your computer's hardware to emulate additional computers, all within 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 provide the ability to emulate a separate operating system (the guest), and therefore a separate computer, from right within your existing OS (the host). For example, you can use a virtual machine to run Unbuntu Linux on Windows 10. The virtual computer environment appears in its own window and is typically isolated as a completely standalone environment, although interactivity between guest and host is often permitted for tasks such as file transfers.

Virtual Machine of Apple computer running Windows
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Everyday Reasons for Using a VM

Virtual Machine software lets developers create and test software on various platforms without actually utilizing a second device. VM environments also allow you to access applications that are native to an operating system different than your own. 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 back to if something were to go wrong such as a malware infection.

Why Businesses Might Use Virtual Machines

Many organizations deploy and maintain several virtual machines. Rather than having a large number of individual computers running at all times, companies opt to have a bunch of VMs hosted on a much smaller subset of powerful servers, saving money not only on physical space but also on electricity and maintenance.

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

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

Common Limitations of Virtual Machines

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

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

Other potential limitations to consider would be the lack of support for certain hardware components as well as possible network constraints. With all of that said, as long as you do your research and have realistic expectations going in, 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 both personal and business usage. 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.