The Different Types of Cloud Computing

The Different Types of Cloud Computing

Cloud computing is not a single concept — it is delivered in different service models that determine how much of the technology stack is managed by the provider versus the customer. Understanding these models is essential for the CLF-C02 exam.

The Three Service Models

Cloud computing services are categorized into three main models:

Management Responsibility:

                    You Manage          Provider Manages
                    ──────────          ────────────────
On-Premises:   │ Applications │
               │    Data      │
               │   Runtime    │        Nothing
               │  Middleware  │
               │     OS       │
               │ Virtualization│
               │   Servers    │
               │   Storage    │
               │  Networking  │

IaaS:          │ Applications │      │ Virtualization │
               │    Data      │      │    Servers     │
               │   Runtime    │      │    Storage     │
               │  Middleware  │      │   Networking   │
               │     OS       │

PaaS:          │ Applications │      │    Runtime     │
               │    Data      │      │   Middleware   │
                                     │      OS        │
                                     │ Virtualization │
                                     │    Servers     │
                                     │    Storage     │
                                     │   Networking   │

SaaS:          Nothing               │  Everything    │
               (just use it)

Infrastructure as a Service (IaaS)

IaaS provides the fundamental building blocks of cloud IT. You get access to networking, computers (virtual or dedicated), and storage. IaaS gives you the highest level of control over your IT resources.

What the provider manages: Networking, storage, servers, virtualization What you manage: Operating system, middleware, runtime, applications, data

AWS Examples of IaaS:

• Amazon EC2 — Virtual servers
• Amazon EBS — Block storage volumes
• Amazon VPC — Virtual networking

Real-world analogy: IaaS is like renting land. You get the plot, but you build and furnish the house yourself.

Platform as a Service (PaaS)

PaaS removes the need to manage the underlying infrastructure and lets you focus on deploying and managing your applications. The provider handles the operating system, patching, and runtime environments.

What the provider manages: Everything in IaaS plus OS, middleware, runtime What you manage: Applications and data

AWS Examples of PaaS:

• AWS Elastic Beanstalk — Application deployment platform
• Amazon RDS — Managed relational databases
• AWS Lambda — Serverless compute (also considered FaaS)

Real-world analogy: PaaS is like renting an apartment. The building is maintained for you, but you bring your own furniture (applications).

Software as a Service (SaaS)

SaaS provides a complete product that is run and managed by the service provider. You simply use the software — you do not worry about any infrastructure, platform, or maintenance.

What the provider manages: Everything What you manage: Just your data and usage

AWS Examples of SaaS:

• Amazon WorkMail — Managed email service
• Amazon Chime — Video conferencing
• AWS Marketplace SaaS products — Third-party SaaS applications

Real-world analogy: SaaS is like staying at a hotel. Everything is provided and maintained for you.

Comparison Table

Choosing the Right Model

The choice between IaaS, PaaS, and SaaS depends on your needs:

• Choose IaaS when you need full control over the environment
• Choose PaaS when you want to focus on code, not infrastructure
• Choose SaaS when you need a ready-to-use application

Pro Tip: On the CLF-C02 exam, you will often be asked to identify which service model a particular AWS service falls under. Remember: EC2 = IaaS, Elastic Beanstalk = PaaS, and fully managed end-user applications = SaaS.

Key Takeaways

• Cloud computing has three service models: IaaS, PaaS, and SaaS
• IaaS provides maximum control — you manage OS, apps, and data (example: EC2)
• PaaS lets you focus on applications — the provider manages the platform (example: Elastic Beanstalk)
• SaaS is a complete application — you just use it (example: WorkMail)
• The higher up the stack you go, the less you manage and the less control you have
• Know which AWS services map to which service model for the exam