What is cloud computing?
How renting computers over the internet works, the three types of cloud, and the difference between IaaS, PaaS, and SaaS.
This week I learned about cloud computing: what it is, the different types of cloud, and the service models you can choose from.
How it works
With cloud computing, you rent computing resources from a provider instead of buying the hardware yourself. The physical machines stay in the provider's data centers, and you access them over the internet.
Even though the hardware isn't with you, you can control it as if it were sitting in your room. You can start servers, install software, store files, and shut everything down when you're done, all from your browser or terminal.
Types of cloud
- Public cloud: the provider's infrastructure is shared between many customers, and you rent the part you need. Examples are AWS, Microsoft Azure, and Google Cloud.
- Private cloud: the infrastructure is used by one organization only, either in its own data center or hosted for it. It gives more control, but costs more to run.
- Hybrid cloud: a mix of both. For example, an organization keeps sensitive data in a private cloud and uses the public cloud for everything else.
Service models
Cloud providers offer three main service models, so you can choose how much you manage yourself:
- IaaS (Infrastructure as a Service): you rent the basic building blocks, like virtual machines, storage, and networking. You manage the operating system and everything on top of it.
- PaaS (Platform as a Service): the provider also manages the operating system and runtime. You just bring your code and deploy it.
- SaaS (Software as a Service): you use finished software over the internet, like Gmail or Microsoft 365. The provider manages everything.
The further down the list you go, the less you manage yourself, and the more you rely on the provider.