DEV Community: Sailee Shingare

What is Virtualization? The Technology Behind the Cloud

Sailee Shingare — Fri, 12 Jun 2026 04:06:45 +0000

By Sailee Shingare | M.S. in Computer Science, Northern Illinois University (NIU)

In my last post, I said the cloud is essentially “someone else’s computer.” But how does one physical computer serve thousands of customers at the same time?

The answer is virtualization.

The Problem Virtualization Solves

Imagine you have a powerful server sitting in a data center. It has 64 CPUs and 256GB of RAM.

You only need 4 CPUs and 16GB of RAM for your application. The rest sits idle — wasted, expensive hardware doing nothing.

Now imagine 16 different companies with the same problem. Each has a powerful server, each using only a fraction of it.

Virtualization solves this by letting one physical server act as many separate computers simultaneously.

What is Virtualization?

Virtualization is the process of creating a software-based version of something that is normally physical — like a computer, server, or network.

Instead of one server running one operating system, virtualization lets you run multiple virtual machines (VMs) on a single physical machine. Each VM behaves like a completely independent computer with its own:

Operating system
CPU allocation
Memory
Storage
Network settings

From the outside, each VM looks and acts like a real physical server. Nobody can tell the difference.

How Does it Work?

The magic happens through a piece of software called a Hypervisor.

A hypervisor sits between the physical hardware and the virtual machines. It manages and allocates resources — deciding how much CPU, memory, and storage each VM gets.

There are two types:

Type 1 Hypervisor (Bare Metal) Runs directly on the physical hardware. No underlying operating system needed. Faster and more efficient. Examples: VMware ESXi, Microsoft Hyper-V, Xen

Type 2 Hypervisor (Hosted) Runs on top of an existing operating system. Easier to set up, great for personal use. Examples: VirtualBox, VMware Workstation

Think of the hypervisor as a traffic controller — directing resources to each VM based on demand.

A Simple Analogy

Think of a large apartment building.

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The physical server is the building. The hypervisor is the building manager. Each virtual machine is a separate apartment — self-contained, private, with its own address and utilities.

The tenants (applications) in each apartment have no idea they’re sharing the same building. To them, they have an entire home to themselves.

Why Virtualization Matters for the Cloud

Cloud providers like AWS, Azure, and GCP use virtualization at massive scale.

When you launch an EC2 instance on AWS, you’re not getting a dedicated physical server. You’re getting a virtual machine running on a physical server shared with other AWS customers — completely isolated from each other.

This is how AWS can offer thousands of virtual servers on demand within seconds. They’re not buying new hardware every time — they’re carving up existing hardware into virtual slices.

Virtualization enables:

Faster provisioning — spin up a new server in seconds
Better resource utilization — no wasted hardware
Isolation — each VM is completely separate from others
Snapshots and backups — save the entire state of a VM instantly
Portability — move VMs between physical servers easily

Virtualization vs The Cloud

These terms are often confused. Here’s the difference:

Virtualization is the technology — the ability to create virtual machines from physical hardware.

The Cloud is the service built on top of virtualization — where someone else manages that virtualized infrastructure and you access it over the internet.

You can have virtualization without the cloud (running VMs in your own data center). But you can’t have the cloud without virtualization.

Try it Yourself

Want to see virtualization in action for free?

Download VirtualBox at virtualbox.org — it’s free
Download an Ubuntu ISO at ubuntu.com/download
Create a new VM in VirtualBox using the Ubuntu ISO
Boot it up

You just ran a completely separate Linux computer inside your Windows or Mac machine. That’s virtualization.

What’s Next?

Now that you understand virtualization, you’re ready for the next step — containers.

Containers took the ideas of virtualization and made them even lighter, faster, and more portable. They’re the foundation of modern cloud-native applications — and the reason Docker and Kubernetes exist.

We’ll cover that in the next post.

What is Cloud Computing? A Beginner’s Guide

Sailee Shingare — Fri, 12 Jun 2026 03:59:56 +0000

By Sailee Shingare | M.S. in Computer Science, Northern Illinois University (NIU)

You’ve heard the word “cloud” everywhere. Your photos are in the cloud. Your company moved to the cloud. Everyone is hiring for the cloud.

But what actually is the cloud?

Let’s break it down simply.

The Cloud is Just Someone Else’s Computer

Seriously — that’s it at its core.

Before the cloud, if a company wanted to run software, they had to buy physical servers, set them up in a room, maintain them, cool them, and replace them when they broke. This was expensive, slow, and painful.

The cloud changed that. Instead of owning hardware, you rent it from companies like:

Amazon Web Services (AWS)
Microsoft Azure
Google Cloud Platform (GCP)

These companies own massive data centers full of servers around the world. You pay only for what you use — like an electricity bill. Need more power? Scale up. Don’t need it anymore? Turn it off.

Why Does It Matter?

Here’s a real example.

Imagine you build a food delivery app. On a normal Tuesday, 500 people use it. But on New Year’s Eve, 50,000 people order at the same time.

Without the cloud, your servers would crash. You’d have to buy enough hardware to handle 50,000 users — even on days when only 500 show up.

With the cloud, you scale up automatically for New Year’s Eve and scale back down the next morning. You only pay for what you used.

That’s the power of cloud computing.

The Three Types of Cloud Services

You’ll hear these terms constantly:

IaaS — Infrastructure as a Service You get the raw building blocks — virtual machines, storage, networking. You manage everything on top of it. Example: AWS EC2 (virtual servers)

PaaS — Platform as a Service You get a platform to build and deploy your app without worrying about the underlying infrastructure. Example: Azure App Service

SaaS — Software as a Service You get a fully built application. Just log in and use it. Example: Gmail, Slack, Zoom

A simple way to remember it:

IaaS = you build everything on a rented plot of land
PaaS = you get a kitchen, you just cook the food
SaaS = someone else cooks, you just eat

Public, Private, and Hybrid Cloud

Public Cloud — Resources shared across many customers. Most common. AWS, Azure, GCP are all public clouds.

Private Cloud — Resources dedicated to one organization. More control, more expensive.

Hybrid Cloud — A mix of both. Some workloads in the public cloud, some on private infrastructure. Very common in large enterprises.

Key Benefits of Cloud Computing

Cost savings — No upfront hardware investment
Scalability — Grow or shrink instantly based on demand
Reliability — Cloud providers offer 99.9%+ uptime guarantees
Global reach — Deploy your app closer to users anywhere in the world
Security — Major providers invest billions in security infrastructure

Where to Start?

If you want to learn cloud computing, start with AWS — it’s the largest cloud provider and has the most learning resources.

Create a free AWS account at aws.amazon.com — the free tier gives you access to 100+ services at no cost for 12 months. Start by launching a simple virtual machine (EC2 instance) and connecting to it. That one exercise teaches you more than hours of reading.

What’s Next?

Cloud computing is the foundation. Everything else — DevOps, Kubernetes, serverless, infrastructure as code — builds on top of it.

In the next post, we’ll dive into virtualization — the technology that makes the cloud possible in the first place.

Stay curious. The cloud isn’t going anywhere.