Cloud computing means that instead of buying a server and keeping it in your own room, you rent processing power and storage from a provider over the internet and pay only for what you use. The "cloud" is really a collection of large data centers whose resources are shared among thousands of customers.
An everyday example#
Think of getting electricity from the national grid instead of building your own power plant. The cloud works the same way: when you need more servers, you switch them on for a few minutes, and when you're done, you switch them off. An online shop gets several times its normal traffic on Black Friday, and with the cloud it can raise its capacity only on those days.
Three main service levels#
- IaaS: you rent only raw infrastructure (virtual servers, network, disks).
- PaaS: you get a ready platform for running applications and don't deal with managing the operating system.
- SaaS: you use ready-made software directly, like an email service or an online accounting tool.
Advantages and limits#
Advantages: a quick start, scalability, no heavy upfront cost and simpler backups. Limits: dependence on the provider, unexpected costs if you don't control usage, and questions about where data is stored.
Note on data location#
Where your data physically lives affects the law, privacy and latency. Before choosing a provider and region, check data residency rules and network latency to your users.