The main types of cloud computing are classified into three service models: IaaS (Infrastructure as a Service), PaaS (Platform as a Service), and SaaS (Software as a Service). The core difference is how much you manage versus how much the provider handles.
Picking the wrong model can mean overpaying for capabilities you don't need — or losing the control your technical team requires. This guide cuts through the jargon so you can choose with confidence.
The Control Spectrum: From IaaS to SaaS
Think of the three models as a continuum. At one end is maximum control (IaaS); at the other is maximum convenience (SaaS):
- IaaS: you manage the OS, middleware, data, and applications. The provider only supplies the physical infrastructure.
- PaaS: the provider adds the OS and runtime environment. You focus on your code and data.
- SaaS: the provider manages everything. You simply use the application through a browser or app.
| Technology Layer | IaaS (you manage) | PaaS (you manage) | SaaS (you manage) |
|---|---|---|---|
| Applications | ✔ | ✔ | ✗ |
| Data | ✔ | ✔ | ✔ (partial) |
| Runtime environment | ✔ | ✗ | ✗ |
| Operating system | ✔ | ✗ | ✗ |
| Servers / network / storage | ✗ | ✗ | ✗ |
IaaS: Infrastructure as a Service
With IaaS you rent the virtual equivalent of physical servers, storage, and networking. No hardware to buy, no racks to maintain — the provider gives you access to those resources by the hour or month.
IaaS Examples
- Amazon Web Services EC2
- Microsoft Azure Virtual Machines
- Google Compute Engine
- DigitalOcean Droplets
When to Choose IaaS
IaaS is the right call when your team has the technical skills to manage servers and needs maximum flexibility: choosing the OS, installing custom software, configuring the network to your exact spec. It's the preferred model for development agencies, DevOps teams, and companies migrating legacy infrastructure to the cloud incrementally.
PaaS: Platform as a Service
PaaS goes one step further: the provider manages the infrastructure and the runtime environment (OS, web server, database, language runtime). You simply push your code and define how it scales.
PaaS Examples
- Heroku
- Google App Engine
- Azure App Service
- AWS Elastic Beanstalk
- Railway, Render (more accessible modern alternatives)
When to Choose PaaS
PaaS is ideal for development teams that want to ship applications fast without spending time on server management. It's especially popular in startups, projects with rapid iteration cycles, and small teams where every engineering hour counts.
If your team wants to accelerate development without losing code-level control, working with specialists like those at elenlace.com can save you weeks of initial setup and configuration.
SaaS: Software as a Service
SaaS is the model most people use every day without realizing it. The provider delivers a complete, ready-to-use application over the internet. No installation, no maintenance on your end.
SaaS Examples
- Google Workspace (Gmail, Docs, Drive)
- Microsoft 365
- Salesforce
- Shopify
- Zoom, Slack, Notion
When to Choose SaaS
SaaS is the best choice when you need standard business functionality — email, CRM, accounting, video conferencing — without investment in infrastructure or custom development. Adoption curves are minimal and maintenance is entirely the provider's responsibility.
The downside: you're fully dependent on the provider for deep customizations, data migrations, and service availability.
Deployment Models: Public, Private, and Hybrid Cloud
Beyond service models (IaaS/PaaS/SaaS), cloud computing is also classified by where the resources live:
- Public cloud: shared infrastructure across multiple customers of the same provider (AWS, Azure, GCP). Cost-effective and highly scalable.
- Private cloud: infrastructure dedicated exclusively to one organization, on-premises or in a dedicated datacenter. Greater control and regulatory compliance.
- Hybrid cloud: a combination of both. Sensitive workloads on the private cloud; variable or public-facing workloads on the public cloud. Increasingly popular with mid-size businesses.
For a deeper look at each variant, visit our cloud computing blog with full guides on public, private, and hybrid cloud architectures.
Key Takeaways
- The three main models are IaaS (infrastructure), PaaS (platform), and SaaS (software) — ordered from most to least technical control.
- IaaS suits teams with DevOps capabilities that need total flexibility over their environment.
- PaaS frees the development team from server administration so they can focus entirely on code.
- SaaS is the fastest path to standard business functionality with no infrastructure investment.
- Deployment models (public, private, hybrid) are an independent dimension — you can have, for example, a SaaS product running on a private cloud.
Not sure which cloud model fits your project? The team at elenlace.com can help you evaluate your technical and business requirements to choose the right solution from day one.
FAQ
What's the difference between IaaS and a dedicated server?
A dedicated server is physical hardware exclusive to you, with a fixed monthly cost and longer provisioning time. IaaS is on-demand virtualization: you pay by the hour, scale in minutes, and never manage real hardware. IaaS is more agile; a dedicated server may deliver higher raw performance for intensive, predictable workloads.
Is PaaS the same as managed cloud hosting?
They're related but distinct. Managed cloud hosting (like cPanel cloud) handles infrastructure and the web server, but the delivery model resembles traditional hosting. PaaS goes further: it provides deployment pipelines, automatic application scaling, managed databases, and per-branch or per-environment setups.
Can I use all three models at the same time?
Yes, and it's common in mid-size and large organizations. For example: SaaS for corporate email (Google Workspace), PaaS to deploy the internal web application, and IaaS for bulk backup storage. This combination lets you optimize cost and control based on the criticality of each workload.
Which model is the most secure?
Security depends on implementation, not the model. IaaS gives you more control but also more responsibility. SaaS shifts more responsibility to the provider but limits your visibility. In all cases, evaluate the provider's certifications (ISO 27001, SOC 2) and your own data governance policies.
Further reading
Other providers and guides worth comparing:
