When a new company starts deploying from scratch, it's often advantageous to begin with Platform as a Service (PaaS). This allows developers to focus on building applications rather than worrying about servers or infrastructure.
On the other hand, when comparing major cloud providers:
- Azure is often considered stronger in Infrastructure as a Service (IaaS).
- AWS is often considered stronger in Platform as a Service (PaaS).
Applications that customers directly use fall under Software as a Service (SaaS)—think Gmail, Office 365, or Discord.
Infrastructure as a Service (IaaS)
In the IaaS model, you request the hardware resources you need, and they are provisioned and managed for you.
For example:
If you ask for a virtual machine with 4 vCPUs, 16 GB of RAM, and 250 GB SSD storage, you'll get exactly that. From there, it's your responsibility to install, configure, and maintain everything from the operating system upward.
Key Characteristics
- Provides hardware resources such as servers, CPUs, memory, storage, and networking.
- Full control is given to the customer to install their own OS, middleware, and applications.
- From a company's perspective, it feels almost like migrating to a new physical server.
Typical Use Cases
- Enterprises with existing on-premises infrastructure often start with IaaS when moving to the cloud. It allows them to replicate their setup with minimal changes.
- Development and testing environments also benefit from IaaS. For example, developers can quickly spin up virtual machines to test apps on environments similar to what clients might use.
Platform as a Service (PaaS)
With PaaS, developers don't worry about the infrastructure. They simply write code, upload it, and let the platform handle the rest.
You're responsible for your application code and data, but everything else—operating system, middleware, runtime, and scaling—is handled by the provider.
Key Features
- Supports multiple runtimes, from web servers and SQL databases to container platforms like Docker.
- Providers offer dozens of available environments: Python, C#, Node.js, Java, and more.
- Includes operating systems, middleware (like VS Code, SQL Server, Firefox), and runtime environments.
Why PaaS?
This is especially advantageous for startups and teams building cloud-native apps from scratch. Instead of spending time configuring infrastructure, developers can focus on coding and delivering value faster.
Software as a Service (SaaS)
SaaS is the model most people are already familiar with. The application is fully built and hosted by the provider. As a user, you simply log in and start using it.
Examples
- Office 365 for productivity tools
- Gmail for email
- Discord for communication
From a company's perspective, SaaS is purchased as a subscription or contract. For example, for corporate email, a business might pay Microsoft for Office 365. All the setup, storage, and maintenance is Microsoft's responsibility—the company only needs to provide account details.
Benefits
- No infrastructure management.
- Quick onboarding and scalability.
- Predictable subscription-based pricing.
Wrapping Up
Understanding IaaS, PaaS, and SaaS is critical for making the right cloud strategy decisions:
- IaaS offers maximum control, ideal for enterprises migrating from on-premises.
- PaaS accelerates development by abstracting infrastructure, making it perfect for startups.
- SaaS delivers ready-to-use software with minimal setup, great for end users and businesses alike.
Each has its place, and most organizations use a mix depending on their goals.