The difference between IaaS, PaaS, and SaaS
More and more software starts to use cloud services.
Cloud services are just a general term and can be divided into three categories.
- IaaS : Infrastructure service, Infrastructure-as-a-service
- PaaS : Platform service, Platform-as-a-service
- SaaS : Software service, Software-as-a-service
What's the difference between them?
IBM's software architect, Albert Barron, once used the pizza analogy to explain the problem. David Ng took it a step further to make it more accurate and understandable.
Imagine you are a restaurant owner looking to start a pizza business.
You could make your own pizza from start to finish, but that would be cumbersome and require a lot of preparation, so you decided to outsource some of the work and use someone else's service. You have three options.
(1) Option 1: IaaS
Others provide the kitchen, stove, gas, and you use that infrastructure to bake your pizza.
(2) Option 2: PaaS
In addition to infrastructure, others also provide pizza crust.
You just sprinkle your toppings on the crust and let him bake it for you. That is to say, all you have to do is design the taste of the pizza (seafood pizza or chicken pizza), and others provide platform services for you to implement your own design.
(3) Option 3: SaaS
Others make the pizza directly, without your intervention, and what you get is a finished product. All you have to do is sell it and at most repackage it with your own logo.
The above three schemes can be summarized into the following picture.
From left to right, the workload undertaken by oneself (the blue part in the figure above) is getting less and less, IaaS > PaaS > SaaS.
Corresponding software development, it is the following picture.
SaaS means that the development, management, and deployment of software are all handed over to a third party. You don't need to care about technical issues, and you can use it right away. The Internet services that ordinary users come into contact with are almost all SaaS. Here are some examples.
- Customer Management Services Salesforce
- Team collaboration service Google Apps
- Storage Service Box
- Storage service Dropbox
- Social Services Facebook / Twitter / Instagram
PaaS provides a software deployment platform (runtime) that abstracts hardware and operating system details and can be seamlessly scaled (scaling). Developers only need to focus on their own business logic, not the bottom layer. The following are all PaaS.
- Heroku
- Google App Engine
- OpenShift
IaaS is the bottom layer of cloud services and mainly provides some basic resources. The difference between it and PaaS is that users need to control the underlying layer and implement the logic of infrastructure usage. The following are all IaaS.
- Amazon EC2
- Digital Ocean
- RackSpace Cloud
Reference link
- SaaS, PaaS and IaaS explained in one graphic, by David Ng
- When to use SaaS, PaaS, and IaaS, by Eamonn Colman
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