What Is a Virtual Machine and How Does It Work

Updated Sep 1, 2022.
What Is a Virtual Machine and How Does It Work

Today’s innovative technologies such as cloud computing owe their existence to the concept of virtualization. Virtualization is the act of creating and running a virtual instance of a computer system using resources that are traditionally bound to hardware. 

Virtual machines let you run an operating system on your desktop in a separate app window. According to Statista, the virtualization software market was worth $63 billion in 2020. Virtual machines make Information Technology (IT) easy to manage and less expensive to run. 

In this article, you will learn everything you need to know about virtual machines. You will learn how a virtual machine works, what it is used for, its benefits, how to set it up, and the best virtual machine software tools. 

What is a Virtual Machine?

A virtual machine – commonly called VM – is the ‘virtual' version of a physical computer. Unlike physical computers, which are physical and tangible parts that make them up, virtual machines are software computers that exist as codes within physical servers. 

One common feature is that it provides the same functionality as physical computers. Like physical computers, it has its memory, storage disks, CPU, and internet connection feature.

Virtual machines can be used to run programs and develop applications. You can host multiple virtual machines on a single physical device. The virtual machines are ‘guests' while the physical machine is the ‘host.' 

Even when you run multiple VMs on a host machine, each virtual machine still has its separate operating system. The use of virtual machines may involve implementing unique hardware, software, or a combination of both.

Physical machine vs Virtual machine
Source: Huawei

How Does A Virtual Machine Work?

The term ‘virtualization' is the process of creating the software model of a physical computer. A virtual machine has its fixed amount of CPUs, memory, and storage space often borrowed from a host machine – i.e., a physical computer – or a remote server. 

You can run a virtual machine in a window as a different computing system. Most times, people use it when they want to work on an operating system that is different from the one installed on the host machine.

Virtual machines even function as some users' entire computer experience – especially those that operate ‘work' computers. The machine is separated from the rest of the host system, meaning that the software program in a virtual machine does not affect or interfere with the host machine's operating system. 

You can use a disc to install an operating system on a virtual machine, and it would install and successfully run like it would on a physical computer. So whenever you want to work on that operating system, you can open the machine program in a window on your desktop computer. 

The operating system that works on the physical computer is called the ‘host'. In contrast, the multiple operating systems on the virtual machine are called ‘guests.' This prevents confusion from any aspect. The guest operating systems are usually stored on a virtual hard drive.

How Does A Virtual Machine Work
Source: ResearchGate

What are VMs Used For?

  • To Run Operating Systems Not Compatible with Your Computer –  Virtual machines allow companies and establishments to run an operating system that behaves like a separate computer in a window on a desktop. They are used mainly by people that want to operate systems of different processing powers. It makes it possible because some software programs are designed to run on some specific operating systems. So if you use an operating system that is not compatible with your choice of software, you can use virtual machines.
  • To Safely Test Run Applications – You can use virtual machines to test run applications in a safe and secured space. 
  • To Optimize Your Computing Resources – You can use VMs to virtualize servers to optimize your computing resources and improve efficiency. 
  • To Carry Out Specific Actions – Virtual machines can also perform specific and risky actions that you cannot do in a host system. Examples of these actions include gaining access to an infected or corrupted data file and test running different operating systems of unknown sources. It is safe to perform these actions because the operating system of the host and guest does not interfere.

Other uses of virtual machines include:

  • Deployment of applications to the cloud.
  • Backing up current operating systems.
  • Running applications on different operating systems.
  • Testing the beta releases of new operating systems.
  • Providing alternative windows to simplify development tests for software developers.

What Are the Benefits of Using VMs?

Although virtual machines run on a physical ‘host' computer with different operating systems, they also have the advantage of working entirely independently of one another (in the case of multiple virtual machines on a host computer) and the physical host machine (desktop). 

A software program, known as a hypervisor, or VM manager, allows you to run different operating systems on other virtual machines simultaneously. That is, you can use a Linux VM on a MAC OS, a MAC VM on a Windows OS, a Windows VM on a Linux OS, or even run an earlier version of an operating system on a more current OS.

Virtual machines are also portable because of the independence feature they possess. You can transport a virtual machine through a hypervisor to another hypervisor on a different host machine within a flash second. The portability and flexibility feature they have, provide so many benefits for the users, such as:

  • Reduced Downtime – Virtual machines can quickly move from one virtual machine manager to another without losing any vital information. This feature makes VMs great solutions for backup if the host machine experiences a downtime unexpectedly.
  • Cost Reduction – The ability to run multiple virtual systems on a physical host environment allows you to spend less on installing and maintaining physical infrastructure. It also improves efficiency when you do not need to maintain as many servers as possible and keeps costs of electricity and maintenance.
  • Scalability – Virtual machines allow users to scale their applications easily by adding more servers (physical and virtual), which will enable them to spread the workload across different virtual machines. Distribution of workload across multiple VMs increases the optimum performance and availability of your applications.
  • Increased Speed – Setting up a virtual machine is relatively easier and faster than setting up a new physical environment for your developers. Also, virtual machines make the development-test process much faster. So if you urgently need to test run a program or run an application on some specific software, you can easily set up your virtual machine to do that without having to interrupt your desktop operations.
  • Guaranteed Security – Because of the ability to run a different operating system on a virtual machine without interrupting the host, you can run applications with controversial security protocols, thereby protecting your host OS. Virtual machines offer optimum security forensics and allow users to analyze computer viruses and isolate them to avoid corrupting the host operating system.

Best Virtual Machine Software

1. VMware Workstation

Overall Best Virtual Machine Software

VMware workstation pro - Virtual Machine Software_

With over 20 years of operation, VMware has been considered the best choice of software that suits the industry standard because its vast functionality covers many virtual needs. 

This software permits advanced solutions, thereby eliminating photo and video quality reduction within the VM even when operating on high-graphics applications. It allows you to run virtual machines from rival vendors, and its networking features allow you to elaborate virtual networks for different virtual machines.

Pros

  • Easy to scale after setup
  • Widely recognized and used
  • Availability of evaluated versions

Cons

  • High pricing
  • 3D support is limited to Windows
  • The configuration might require changes

Pricing

VMware workstation pro - Virtual Machine Software - pricing

There are two versions of VMware Workstation: Workstation Player and Workstation Pro. The player version is free for users, and it can support up to 200 guest operating systems. Also, it allows file sharing between the host computer and the guest. This version does not have some advanced functionality, such as running multiple virtual machines at a time.

The Pro version opens you to features beyond the trial mode and has Unity mode for MAC users. Both versions are also compatible with Windows 10 OS and 64-bit Linux OS.

2. VMware Fusion

Best VM Software for Mac Users

VMware Fusion - Desktop Hypervisors for Mac

This application is designed by the same team that created VMware Workstation, and it is designed for Windows and Linux. VMware Fusion offers the same user experience that Workstation offers Mac OS. 

Like VMware Workstation, Fusion's basic version is free to use and available for personal use only. The Pro version is used primarily by large businesses and individuals who need access to advanced features. It has some features like mixed-retina configuration and 5K Mac displays and is also compatible with Mac OS.

Pros

  • Free basic version
  • Supports a wide range of Mac OS displays.

Cons

  • The application can be sluggish sometimes.

Pricing

VMware Fusion - Desktop Hypervisors for Mac - pricing

VMware Fusion has three pricing plans: VMware Fusion 12 Player, VMware Fusion 12 Pro, and VMware Fusion 12 Pro+. The VMware Fusion 12 Player is licensed for commercial use and the VMware Fusion 12 Po is suitable for developers and IT professionals.

The VMware Fusion 12 Pro+ offers you the ability to run Windows on Mac and other operating systems simultaneously. It offers technical support. 

3. Oracle VM VirtualBox

Best Virtual Machine Software with Free Options

Oracle VM VirtualBox - virtualization product for enterprise and home use

Oracle VM VirtualBox supports many guest operating systems, including Windows XP through to Windows 10 and Windows NT. It can also run virtual machines with Linux 2.4 and the versions above. 

You can run a Mac OS in a virtual machine using the VirtualBox software application, although the host computer must be operating on a Mac OS. With Oracle VM VirtualBox, you can run multiple VMs on VirtualBox simultaneously and transfer one virtual machine to another host working on a different OS.

VirtualBox is compatible with other host platforms like:

  • Solaris 11
  • Server 2012, Server 2012 R2, 2016, and 2019
  • Windows 8.1 and 10

Pros

  • Free basic version
  • User-friendly Interface
  • Stable software program

Cons

  • Requires high-class hardware with large RAM for efficient performance
  • Requires additional download for more features

Pricing

As an open-source virtual machine, Oracle VM VirtualBox offers users free options.

4. Parallels Desktop

Best VM Software for Mac and Windows Operating Systems (OS)

Parallels Desktop - VM Software for Mac and Windows Operating Systems (OS)

This software is a perfect choice for long-time Mac users that occasionally need to run Windows OS on a separate system. Parallels Desktop makes it easy for users to run both operating systems side by side. It helps users to optimize hardware resources for them to have the Windows experience. 

Parallels offer most of the features in a paid virtual machine, and it has some specific features for Mac users. You can share files between two different operating systems. Cloud-based storage space is included in the application, and it can be distributed between Windows and Mac Operating Systems (OS).

Pros

  • Multiple versions that allow flexibility
  • Compatible with Windows, Linux, Chrome OS, and Mac OS
  • Ability to monitor memory usage

Cons

  • Subscription plans mandate yearly renewals
  • High resource consumption

Pricing

Parallels Desktop - VM Software for Mac and Windows Operating Systems (OS) - pricing

There are three versions of the Parallels application, and each of them is suitable for a specific audience. You can use the standard version if you are switching from Windows to Mac for the first time. 

The pro version is for software programmers and developers, software testers, and other sophisticated users. It has 24/7 email and chat support and pro networking tools. 

The business version includes every feature from the other two versions, plus management tools and centralized administration.

5. Hyper-V Manager

Best Virtual Machine Software for Windows 10 Users

Hv Manager - Virtual machine manager for Hyper-v with web interface

Microsoft Corporation introduced this software for professionals and enterprises. It is an in-built system that supports linking with a Windows 10 host OS and other guest operating systems. This virtual machine also supports various versions of Linux OS and old systems like MS-DOS.

Pros

  • Application already installed in some Windows 10 versions.
  • Optimum performance with deep linking.

Cons

  • Not a Windows 10 Home supported application.
  • The deep linking makes it impossible for other VM solutions to work simultaneously.

Pricing

Hv Manager - Virtual machine manager for Hyper-v with web interface - Pricing

Hyper-V manager has two pricing plans: server license and maintenance renewal. 

6. QEMU

Best Free VM Software for Linux Users

QEMU - a generic and open source machine emulator and virtualizer

QEMU is currently the best choice of VM software for worldwide Linux OS users because of its easy-to-use emulation tools and zero-dollar price tag. Running specific virtual machines like KVM on QEMU gives an outstanding performance that users nearly forget they are running a VM.

The software is compatible with:

  • Most Linux versions OS
  • 32-bit and 64-bit Windows OS
  • Mac OS from version 10.5 and above.

Pros

  • Dual function of a VM host and machine emulator
  • Free to use

Cons

  • Only for Linux users
  • Has a sophisticated interface

Pricing

QEMU is free to use.

Setting Up a Virtual Machine

Having known and decided on the virtual machine app to use, download and install on your host computer. Once you have installed it, setting up is a straightforward process. Let us go through the steps in VirtualBox (as an example) one after the other so you can see how easy it is to do it without cleaning a drop of sweat.

Step 1: Select Your Preferred Operating System

After installing, open the virtual machine application and click on the ‘New' button to create a new virtual machine. You will be guided through the process by the application, which will first request the choice of OS you want to install.

Create Virtual Machine - Name and operating system
Source: Virtualbox

If you start typing the name of the OS in the appropriate box, you will most likely see related options popped up for you to pick the type and version. If it does not bring your choice, type it fully into the box and click ‘Next.'

Step 2: Set The Memory Size You Need

The operating system you choose will automatically preselect some options for you. If you are not okay with what is selected, you can change it to your choice. You will be asked to choose the memory you want to assign to the VM (Virtual Machine). 

A default figure is set, but you can adjust it if you want more or less. If you are okay with the default, click on ‘Next' but know that you can change the figures later.

Step 3: Create A Virtual Hard Disk Drive

The next thing is to create a virtual hard disk drive for the virtual machine. Select the option that tells you to create one if you don't have an existing virtual hard disk drive. 

Afterward, you will be asked to either choose between a fixed-size disk or a dynamically allocated disk. If you pick the fixed-size disk drive, you will be asked to select your preferred disk size, and the disk created will be that big from the creation. 

But if you pick the dynamically allocated disk drive, you will also choose your desired disk drive size, but the created file will grow to the size you initially picked as you continue to use it. It is better to pick the fixed-size disk size because they perform better while consuming more disk space. Also, it allows your virtual machine to be more responsive.

Create Virtual Machine - Hard disk
Source: Virtualbox

Step 4: Select The Size Of The Hard Disk Drive You Want To Create

The next step after picking your choice of a hard disk drive is to set your preferred size. You can either go with the default or make changes where necessary. When you click on ‘create,' then your virtual hard disk is created. 

Create Virtual Machine - File location and size
Source: Virtualbox

After creation, you will be taken back to the main app window, where your new virtual machine will appear. You can now run your new virtual machine by selecting it and hitting the ‘start button.

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Martin Luenendonk

Editor at FounderJar

Martin loves entrepreneurship and has helped dozens of entrepreneurs by validating the business idea, finding scalable customer acquisition channels, and building a data-driven organization. During his time working in investment banking, tech startups, and industry-leading companies he gained extensive knowledge in using different software tools to optimize business processes.

This insights and his love for researching SaaS products enables him to provide in-depth, fact-based software reviews to enable software buyers make better decisions.