A virtual machine (VM) is like a computer inside your computer! It's a software-based version of a real computer. It runs an operating system and apps just like a real one, but it's not physical, it's virtual.
How does it work? A VM runs on top of special software called a hypervisor (or virtual machine monitor). The hypervisor manages the VMs, gives each one what it needs, and keeps them isolated from each other. One physical computer (the host) can run many virtual machines at once.
Examples of what VMs let you do: run Windows on a Mac (or another OS without changing your main one), try Linux safely, learn and experiment without changing your main computer, and run server software that hosts websites, databases, and more.
What can go wrong (or be careful about)? VMs share the host's resources, so running too many can slow things down, and a VM still needs enough memory and storage to run well. But they're great for testing, learning, and development.
Here's the big idea, in a recap. A virtual machine is a computer inside a computer, a hypervisor runs several VMs, each VM uses its own OS and apps, and it's useful, flexible, and powerful.
Remember: a virtual machine is software that acts like a real computer, it runs inside a real one, one computer can run several, and VMs are perfect for trying new things safely. Virtualize your world!
What to remember
- A virtual machine is a computer made of software.
- It runs inside a real (physical) computer.
- One computer can run several VMs at once.
- VMs are great for testing, learning, and trying new OSes safely.
Words to know
- Virtual machine (VM)
- A software-based computer inside a real one.
- Hypervisor
- Software that runs and manages VMs.
- Host
- The real computer the VMs run on.
- Isolated
- Kept separate from the host and other VMs.
For grown-ups
A virtual machine is a software emulation of a computer that runs on a hypervisor atop physical hardware, with its own OS and apps, isolated from the host and other VMs. VMs enable running multiple OSes on one machine, safe testing/sandboxing, server consolidation, and cloud computing. (Containers are a lighter, OS-level cousin.)
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