What Is Cloud Computing?
What Cloud Computing Means and How It Works
What is cloud computing? In short, it means using computing resources, such as servers, storage, databases and software, over the internet on demand, instead of owning and maintaining the hardware yourself. The word “cloud” is a metaphor for the internet, which is often drawn as a cloud in network diagrams.
In traditional IT, a company buys servers, installs them in its own room or building, and pays for them whether they are busy or idle. In the cloud model, a provider such as Amazon Web Services, Microsoft Azure or Google Cloud owns the hardware in its data centers. Customers request resources through a web console, a command-line tool or an API (application programming interface, a set of rules that lets one program request services from another). Resources are usually ready within minutes.
The provider uses virtualization, software that splits one physical machine into several isolated virtual machines. Each customer sees only its own resources, while the underlying hardware is shared across many customers. This sharing is a large part of why the model can be offered at flexible prices.
Cloud services come in three main service models, which are compared in IaaS vs PaaS vs SaaS.
The Five Essential Characteristics of Cloud Computing
The US National Institute of Standards and Technology (NIST) defines cloud computing through five essential characteristics. These are the features that separate cloud services from traditional hosting and in-house servers.
- On-demand self-service. You add or remove resources yourself, without asking a person to install hardware.
- Broad network access. Services are reachable from laptops, phones and other devices over standard networks.
- Resource pooling. The provider serves many customers from shared hardware, and customers generally do not control the exact physical location of their resources.
- Rapid elasticity. Capacity can grow and shrink with demand, so a site can absorb a traffic spike and then release the extra capacity.
- Measured service. Usage is metered, so you pay for what you consume, such as compute hours or gigabytes stored, rather than a fixed purchase price.
Pay-per-use billing is the characteristic that changes budgeting the most. Costs follow usage, which can save money for variable workloads but makes bills harder to predict. The cloud pricing models article explains how these charges are structured.
Frequently asked questions
Is cloud computing the same as the internet?
No. The internet is the global network that connects computers. Cloud computing is a way of using servers, storage and software that are delivered across that network. The internet is the route, and cloud computing is the service you receive through it.
Is cloud computing secure?
It can be, but security is shared between the provider and the customer. The provider protects the physical data centers and the underlying platform. The customer is responsible for access control, encryption settings and its own applications. Many cloud security incidents involve customer misconfiguration rather than failures in the provider’s infrastructure.
Do I need to be a developer to use cloud computing?
Not always. Many cloud products, such as file storage, email and business software delivered as SaaS, are used without writing any code. Building custom applications or managing infrastructure usually requires technical skills. Most people use cloud services through a ready-made product rather than by configuring servers themselves.