Operating systems

Virtualization Basics

Overview

Virtualization allows one physical computer to run multiple operating systems at once, which is how cybersecurity practice labs stay safe and isolated.

Key concepts

  • Virtual machine, host, guest, hypervisor
  • VirtualBox and UTM
  • Snapshots

Tools & techniques

ToolPurposeWhen to use
VirtualBoxFree hypervisor for creating/running VMsHome lab, Linux practice, isolated testing
UTMVirtualization on Apple silicon MacsRunning Linux VMs on M-series Macs

How it works

Overview

Virtualization allows one physical computer to run multiple operating systems at the same time.

Virtual Machine (VM)

A software-based computer with virtual CPU cores, RAM, storage, network adapters, and an OS of its own.

Host

The physical computer running the virtualization software.

Guest

The operating system running inside the virtual machine.

Hypervisor

Software that creates and manages virtual machines.

VirtualBox

Free virtualization software used to create and run VMs — useful for Linux labs, cybersecurity practice, and testing software in an isolated environment.

UTM

A virtualization program commonly used on Apple silicon Macs — can run VMs such as Linux distributions.

Snapshot

Saves the current state of a VM. If something breaks during a lab, you can restore the snapshot and return the VM to its earlier state.

Why Virtual Machines Matter

VMs create a safer learning environment for cybersecurity — you can run Kali Linux, Ubuntu, Windows, or intentionally vulnerable systems without installing them directly on your main computer. For example, run Kali Linux and a vulnerable practice VM on an isolated virtual network. Only scan or test systems you own or have permission to test.