What Is a Virtual Machine (VM) and How Does It Work?

1What Is a Virtual Machine?

A virtual machine (VM) is a software-based emulation of a physical computer — it runs its own operating system and applications as if it were a standalone machine, while actually sharing the underlying physical hardware with other VMs.

This lets a single physical server run multiple isolated 'computers' simultaneously, each unaware of the others, dramatically improving hardware utilization compared to dedicating one physical machine per workload.

2How Virtual Machines Work

A hypervisor is the software layer that makes virtualization possible: it sits between the physical hardware and the virtual machines, allocating CPU, memory, storage, and network resources to each VM and keeping them isolated from one another.

Each VM believes it has exclusive access to its own virtual CPU, virtual memory, and virtual disk, when in reality the hypervisor is translating those virtual resources into slices of the real physical hardware underneath.

3Type 1 vs Type 2 Hypervisors

Hypervisors split into two categories based on where they sit relative to the host operating system.

• Type 1 (bare-metal): runs directly on the physical hardware with no host OS underneath — used in data centers and cloud platforms for maximum performance and isolation.
• Type 2 (hosted): runs as an application on top of an existing host operating system — used for local development, testing, and running a different OS on a personal computer.

4VMs vs Containers

The key difference is what gets virtualized: a VM virtualizes the entire hardware stack, including its own full operating system kernel, while a container shares the host machine's OS kernel and only packages the application plus its dependencies.

This makes containers significantly lighter and faster to start than VMs, but VMs provide stronger isolation since a container escape can potentially reach the shared host kernel, while a VM breakout must cross the hypervisor boundary.

5VMs and Cloud Computing

Cloud providers rent out virtual machines by the hour, minute, or second, letting customers spin up computing power on demand without buying or maintaining physical servers — this is the foundation of Infrastructure-as-a-Service (IaaS).

A customer can launch a VM sized to their exact CPU, memory, and storage needs, scale it up or down, and pay only for what's actually used, compared to the fixed capital cost of owning physical hardware.

6Common VM Use Cases

VMs remain the standard choice for a range of workloads even as containers have taken over much of application deployment.

• Running legacy applications that require an older or specific operating system version.
• Isolating untrusted or high-risk workloads with strong security boundaries.
• Testing software across multiple operating systems from a single physical machine.
• Hosting traditional enterprise applications that expect a full OS environment.
• Providing the underlying compute layer that container orchestration platforms themselves run on top of.

7Getting Started with VMs

Free, local hypervisor tools let you create and experiment with VMs on your own machine before touching a cloud bill — a practical way to build intuition for how hypervisors allocate resources.

SkillVeris's MLOps course and broader DevOps learning path cover VMs and containers together as the infrastructure foundation for deploying and scaling real applications.