Cloud Computing: How do IaaS, PaaS and SaaS come together?

Cloud computing has transformed the way we conduct business. Making IT infrastructure, platforms, and software programmes available over the internet has changed the way businesses store, access, and manage data. Giving organisations the flexibility and scalability, they require to meet their ever-changing needs.

Cloud computing is composed of layers, which can be described as a stack. Each layer builds on the previous one to form a single application, and the degree of responsibility placed on the end user varies as a result. We’ve already taken a look at each layer of the cloud computing stack separately: IaaS: Infrastructure as a Service, PaaS: Platform as a Service, and SaaS: Software as a Service. But you may feel a bit confused about what their differences are and which one you should choose.

How do they all stack up?

Let’s take a look at a quick summary of what each cloud computing model entails:

• Infrastructure as a Service (IaaS) is the foundation of the cloud computing stack, where a service provider handles servers, disks, network security and firewalls, storage, and virtualisation. You can access computer hardware in a cloud-based environment for a monthly fee, but you must still manage the operating system, data, applications, middleware, and runtimes. Amazon Web Services (AWS), Microsoft Azure, and Google Compute Engine are a few examples.
• On top of that is Platform as a Service (PaaS): the technical stack required for application development, which includes development tools and data management. A service provider gives you access to a collection of related applications or tools that are designed to assist businesses in performing complex interrelated tasks such as software development and testing. PaaS is less expensive and simpler to manage than IaaS, but it is less scalable. Google App Engine, AWS Elastic Beanstalk, and Windows Azure are some examples.
• There’s also Software as a Service (SaaS), which is a web-based software deployment model in which software programs are made available via the internet. Because the applications are all run in the cloud, they can be accessed from any device with an internet connection. The primary distinction between PaaS and SaaS is that SaaS provides a finished workload, whereas PaaS provides the tools required to assist a business in creating and managing its own workload. Examples of SaaS include Shopify, Google Workspace, and Microsoft Office 365.

Which Cloud Computing Model Should You Choose?

You can use any or all of the cloud computing models, depending on how much you can and want to manage yourself and how much you want your service provider to manage for you.

Albert Barron, Principal Architect, Financial Services at Google, describes the differences between IaaS, PaaS and SaaS so well in his Pizza as a Service analogy. In each example the result is the same, you get to eat some pizza, but in some cases, you have to do all the work whereas in the other instances other people are doing all the work for you.

Pizza as a Service

1. In the first instance, he compares traditional on-premises computing to making your own pizza at home. You are responsible for purchasing all of the ingredients and making your own dough.
2. Infrastructure as a Service (IaaS) is when you buy a pre-made plain pizza base and then at home you add the toppings and bake the pizza yourself.
3. Platform as a Service (PaaS) simplifies cloud computing even further. It entails placing an order for a pizza to be delivered to your home. The pizza arrives ready to eat, but you will still eat it at home, using your table and chairs and possibly adding some drinks to go with it.
4. Finally, Software as a Service (SaaS) is when you decide to drive to a restaurant and eat a pizza that someone else made. All of the work has been done for you, and all you have to do now is enjoy the results.