What Is Cloud Computing, in Plain Terms?
- Filed
- Length
- 3 min
In this page (8)
- An everyday comparison
- The three main service models
- Public, private and hybrid cloud
- Why organisations use it
- The trade-offs to weigh
- Where cloud computing meets AI
- First steps for a small team
- In one sentence
"It's in the cloud" has become such a common phrase that it is easy to forget what it actually means. There is no actual cloud, of course. There are very large buildings full of computers, owned and run by service providers, and you reach them over the internet. Cloud computing is simply the practice of using those remote computers for storage, processing or software instead of relying only on equipment in your own office or home.
An everyday comparison
Think about electricity. Very few businesses run their own power station. They plug into the grid, use what they need and pay for it. Cloud computing applies a similar idea to computing resources. Instead of buying a server, installing it in a cupboard and maintaining it, you rent capacity from a provider and access it when you need it.
If you have used web-based email, shared documents that several people edit at once, or a photo backup on your phone, you have already used cloud computing.
The three main service models
Cloud services are often grouped into three layers, depending on how much the provider manages for you.
| Model | What you get | Everyday example |
|---|---|---|
| Software as a Service (SaaS) | Finished applications you use through a browser or app | Web email, online accounting, video meeting tools |
| Platform as a Service (PaaS) | A ready environment for building and running your own applications | A hosted platform where developers deploy a web app without managing servers |
| Infrastructure as a Service (IaaS) | Raw computing building blocks such as virtual machines, storage and networks | Renting virtual servers to run a company's own software |
Most small businesses mainly use SaaS. Technical teams are more likely to work with PaaS and IaaS.
Public, private and hybrid cloud
- Public cloud — resources shared among many customers on the provider's infrastructure, with each customer's data kept separate.
- Private cloud — infrastructure dedicated to a single organisation, either on its own premises or hosted by a provider.
- Hybrid cloud — a mix, where some systems stay in-house and others run in a public cloud, often connected so data can move between them.
Why organisations use it
Flexibility
Capacity can be added or reduced as needs change, which helps businesses with busy seasons or rapid growth.
Lower upfront spending
Instead of a large purchase of hardware, costs become an ongoing operating expense. Whether that works out cheaper over time depends on how the service is used.
Access from anywhere
Staff can reach files and tools from home, on the road or at a client's office, which is one reason remote and hybrid work spread so easily. A modest work laptop can feel far more capable when the heavy lifting happens elsewhere.
Less maintenance
The provider looks after hardware failures, physical security and much of the patching, freeing small teams from tasks they may not have the skills or time for.
The trade-offs to weigh
- Ongoing costs can creep up. Subscriptions and usage-based bills are easy to start and easy to forget. Review them regularly.
- You depend on a connection. If your internet goes down, so does access to cloud tools, unless they offer offline modes.
- Shared responsibility for security. Providers secure their infrastructure, but customers remain responsible for strong passwords, access rights and settings. Many cloud incidents stem from misconfiguration rather than the provider being breached.
- Data location and rules. Some industries and regions have requirements about where data is stored. Check the provider's options and your own obligations.
- Switching can be hard. Moving large amounts of data or rebuilding workflows with another provider takes effort, so think about exit options at the start.
Where cloud computing meets AI
Many of the artificial intelligence tools that have appeared in recent years run in the cloud, because they need more processing power than a typical laptop has. Our article on the spread of AI tools looks at how those services are changing everyday digital work.
First steps for a small team
- List the software and files you rely on and where they currently live.
- Identify one area, such as file sharing or backups, where a cloud service would remove a clear pain point.
- Read the provider's terms on data storage, support and cancellation.
- Turn on two-step verification and set sensible access permissions from day one.
- Review usage and costs after a few months before moving anything else.
In one sentence
Cloud computing is renting computing resources over the internet instead of owning and running them yourself, which brings flexibility and convenience in exchange for ongoing costs, reliance on a connection and a share of the security work that stays firmly with you.