---
title: "Cloud"
description: "Cloud computing is an on-demand model for accessing IT resources over the internet. Learn the IaaS, PaaS and SaaS models and how the cloud is used."
url: "https://nodea.io/en/glossary/cloud"
lang: "en"
updated: "2026-07-13"
---

# Cloud

> Cloud, or cloud computing, is a model of delivering computing power, storage and applications over the internet on demand, with billing based on actual usage.

**Cloud**, or cloud computing, is a model of delivering IT resources — computing power, storage, databases and applications — over the internet, on demand and billed by actual usage. Instead of buying and maintaining their own servers, users rent the resources they need from a cloud provider and scale them according to current demand. The cloud removes the burden of managing physical infrastructure from the organization.

## How cloud computing works

The foundation of the cloud is [virtualization](https://nodea.io/en/glossary/virtualization), which allows many isolated virtual machines to run on a single physical server. The provider maintains distributed data centers, and management software allocates resources and moves workloads between machines. As a result, the service stays available even when a single server fails.

The cloud is divided into three main service models. **IaaS** ([Infrastructure as a Service](https://nodea.io/en/glossary/iaas)) provides raw infrastructure: virtual machines, networking and storage. **PaaS** ([Platform as a Service](https://nodea.io/en/glossary/paas)) adds a ready environment for running applications. **SaaS** ([Software as a Service](https://nodea.io/en/glossary/saas)) delivers finished software in the browser.

## Practical applications

The cloud model shines in projects with variable load and where launch speed matters.

- **Elastic scaling** — an online store can add resources during a campaign and reduce them afterward.
- **Backups and disaster recovery** — data replicated across data centers protects against loss.
- **Fast deployments** — a new environment spins up in minutes, with no hardware purchase.

Cloud computing has become a foundation of modern IT and, for many companies, a natural complement to or alternative to a classic dedicated server. Hybrid models that combine on-premises resources with the public cloud are also increasingly popular.

### How does the cloud differ from traditional hosting?

With traditional hosting you use a specific server with fixed parameters. The cloud lets you scale resources up and down on demand and pay for actual usage, rather than reserving a fixed capacity in advance.

### Is data in the cloud safe?

Reputable cloud providers use encryption, backups and data center redundancy. Security also depends on the customer's configuration, however, including access permissions and password protection.

## Related

- [IaaS (Infrastructure as a Service)](https://nodea.io/en/glossary/iaas)
- [PaaS](https://nodea.io/en/glossary/paas)
- [SaaS](https://nodea.io/en/glossary/saas)
- [Virtualization](https://nodea.io/en/glossary/virtualization)
- [Serverless computing](https://nodea.io/en/glossary/serverless-computing)

---

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