Virtualization vs cloud computing: what are the differences?

The difference between virtualization and cloud computing is that virtualization is a technology, while cloud computing is a service. Virtualization splits one physical server into several virtual servers, which the company buys and manages. Cloud computing means resources (servers, storage, applications) rented from a provider on demand and paid for based on usage.

Virtualization and cloud computing are two technologies developed to make the best possible use of computing resources while also reducing their cost. Both also come up often in discussions about high availability and redundancy.

Although it’s not unusual to hear people talk about them as if they were the same thing, they’re very different approaches to the same problem: how to make the best use of the resources available. They differ in many ways, and that matters when you choose between them.

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Virtualization: several servers on the same hardware

Before virtualization, if you needed more computing power for an application, you had to buy additional hardware.

Redundancy systems relied on duplicate hardware sitting on standby in case something failed.

The problem was that as processors became more powerful and gained more and more cores, a lot of computing resources went unused.

Obviously, this cost companies a lot of money.

That’s how virtualization came about.

Simply put, virtualization is a technique that lets you run several servers on the same hardware.

The physical server, called the host, runs a program called a hypervisor (for example VMware ESXi, Microsoft Hyper-V or Proxmox VE), which controls access to the physical resources: processor, memory, disks and network.

One or more virtual servers then run on top of the hypervisor, each with its own operating system.

For the virtual server, the hypervisor is transparent: the operating system installed on it works just as it would on an ordinary server and doesn’t need to be modified. This allows server consolidation, which reduces hardware costs.

Fewer physical servers also means less energy consumed, which cuts costs even further.

Most virtualization platforms make it easy to move virtual servers from one physical host to another, often without any downtime. That way, administrators can very easily redistribute servers based on resource demand or move a virtual server off a faulty physical server.

Virtualization reduces complexity because it cuts the number of physical servers, but the company still has to buy servers and licenses and maintain the infrastructure. Its biggest benefit is lowering the cost of that infrastructure by making the most of the physical resources.

Don’t confuse virtual machines with containers (Docker, for example): a container doesn’t have its own operating system; it uses the host’s and isolates only the application, so it’s lighter but less separated from the rest of the system.

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Cloud computing: metered resources, you pay for what you use

Although virtualization can be used to deliver cloud computing, cloud computing is something else entirely.

Cloud computing can look like virtualization, because your application seems to run on a virtual server that isn’t tied to any particular physical server. From that point of view, they really are similar.

However, cloud computing is better described as a service, in which virtualization is part of the physical infrastructure.

Cloud computing grew out of the concept of utility computing. In essence, utility computing was the belief that computing resources and hardware would become a commodity, to the point where companies would buy computing resources from a shared pool and pay only for the processor, RAM, storage and bandwidth they use.

These resources are metered, so you pay only for what you use, just as you pay your electricity provider for power. That’s where the name utility computing comes from. Cloud services are usually distributed across several servers and even across several data centers.

This provides redundancy, high availability and even geographic redundancy. It’s also where the cloud’s flexibility comes from.

It’s easy to add resources for your application: you simply use them, just as you use electricity when you need it. Cloud computing was designed for scalability from the start.

The biggest drawback of cloud computing is, of course, that you don’t control the servers. Your data sits with the provider, and you have to trust that it’s safe. Many cloud services offer SLAs (service level agreements) that promise a certain level of availability and security, but it’s essential to read the fine print too. A cloud service failure can lead to data loss, which is why data in the cloud also needs a separate backup.

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A practical comparison: virtualization vs cloud computing

Virtualization

Virtualization is a technology that lets you create several simulated environments or dedicated resources from a single physical hardware system. A program called a hypervisor runs directly on that hardware and lets you split one system into separate, distinct and secure environments called virtual machines (VMs). Virtual machines rely on the hypervisor’s ability to separate the machine’s resources from the hardware and distribute them as needed.

Cloud computing

Cloud computing is a set of principles and approaches through which computing, networking and storage resources, services, platforms and applications are made available to users on demand, over the internet or any other network. These resources come from clouds, meaning pools of virtual resources orchestrated by management and automation software, so that users can access them on demand through self-service portals, with automatic scaling and dynamic resource allocation.

In short

• What it is: virtualization is a technology; cloud computing is a service, usually built on virtualization.
• Who owns the hardware: with virtualization, the company; in the cloud, the provider.
• How you pay: with virtualization, an upfront investment in servers and licenses, plus maintenance; in the cloud, a subscription or pay-as-you-go.
• How easily you scale: with virtualization, up to the limit of the servers you have; in the cloud, almost instantly.
• Who’s in control: with virtualization, the company has full control of the servers and data; in the cloud, you depend on the provider and its SLA.

What should you choose in 2026: on-premises virtualization or the cloud?

You don’t have to choose just one: many companies combine virtualized servers at the office with cloud services, an approach called hybrid cloud.

• The cloud suits email and documents (Microsoft 365 or Google Workspace), applications whose usage varies, and companies that don’t want to buy and maintain servers.
• On-premises virtualization suits you when you have legacy applications that can’t be moved to the cloud, large volumes of data used daily at the office, or strict rules about where data is stored.

A few things have changed since we wrote this article in 2021:

• After Broadcom bought VMware in November 2023, VMware licenses moved to subscription only, sold in bundles, and for many companies the cost went up. Some companies switched to other virtualization platforms or moved some of their servers to the cloud.
• Since September 2025, the EU Data Act has applied, requiring cloud providers to make it easier for you to switch to another provider. From January 2027, providers can no longer charge you for switching.
• Even in the cloud, some things remain the company’s responsibility: accounts, two-step verification, correct configuration and data backup. The provider is responsible for the infrastructure, not for a compromised account or a wrong setting.

See also our articles on local server or cloud server, what IaaS is and IT explained simply: virtualization and cloud computing. If you’re not sure which option suits you, a free IT audit starts from the servers and applications you have now.

RezolvIT is an IT outsourcing company experienced in implementing cloud technologies and enabling its clients’ employees to work from home. If we’ve convinced you, ask for a quote.