What Are the Types of Cloud Computing?
What Are the Types of Cloud Computing? !
A cloud computing system delivers computing resources such as servers, storage, databases and software over the internet, so you rent what you need instead of buying and running hardware yourself. Businesses adopt it to launch faster, scale up or down on demand, and turn big upfront equipment purchases into usage-based costs.
The “types” of cloud computing fall into two groups. Deployment models describe where the cloud runs and who can use it: public, private, hybrid and multi-cloud. Service models describe what you get: infrastructure (IaaS), platform (PaaS) or finished software (SaaS). This guide explains both, compares them side by side, and shows how to pick the right mix.
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TL;DR
- There are four common deployment models (public, private, hybrid, multi-cloud) and three core service models (IaaS, PaaS, SaaS).
- Deployment answers “where does it run?” Service answers “how much do I manage myself?” You choose one of each.
- Most organizations mix models: 70% of respondents in Flexera’s 2025 survey use at least one public and one private cloud.
- Moving to the cloud does not move your compliance duties to the provider. You still answer for your data and users.
- Start from your workload, your regulations and your team’s skills, not from a vendor’s feature list.
Table of Contents
- What Is a Cloud Computing System?
- Cloud Deployment Models: Where Your Cloud Lives
- Cloud Service Models: How Much Do You Manage?
- Side-by-Side Comparison of Cloud Computing Types
- Benefits and Challenges of Cloud Computing
- Real-World Use Cases
- How to Choose the Right Cloud Model
- Our Perspective: Pick the Simplest Model That Meets Your Rules
- Getting Help With Your Cloud Move
- Conclusion
- FAQ
- Sources
What Is a Cloud Computing System?
The U.S. National Institute of Standards and Technology (NIST) defines cloud computing as a model for convenient, on-demand network access to a shared pool of configurable resources that can be provisioned quickly with minimal management effort. Its official definition lists five essential characteristics:
- On-demand self-service: you provision resources yourself, without calling a salesperson.
- Broad network access: you reach them from laptops, phones and other devices over the network.
- Resource pooling: the provider serves many customers from a shared pool.
- Rapid elasticity: capacity grows and shrinks as demand changes.
- Measured service: usage is metered, so you pay for what you consume.
The same document names three service models (SaaS, PaaS, IaaS) and four deployment models (public, private, community and hybrid). Many industry guides replace “community” with “multi-cloud” because that is how companies talk about their setups today. We cover both ideas below.
Analogy: think of a cloud computing system like electricity. You don’t build a power plant to run your office. You plug in, use what you need, and get a bill. The difference is that with cloud you also decide how much of the wiring you want to handle yourself.
Cloud Deployment Models: Where Your Cloud Lives
Deployment models describe who owns the environment, who shares it and where your workloads run.
Public cloud
A third-party provider owns the data centers and rents resources to many customers over the internet. You never see the hardware. You create an account, choose a configuration and start working within minutes.
- Strengths: low entry cost, near-unlimited capacity, fast experimentation, no hardware to maintain.
- Watch-outs: costs can drift without monitoring, and you have less control over the underlying infrastructure.
- Typical fit: startups, web and mobile apps, development and testing, workloads with unpredictable traffic.
Private cloud
A private cloud is dedicated to a single organization. It can sit in your own data center or be hosted by a provider, but the resources are not shared with other customers.
- Strengths: maximum control over configuration, data location and security policies.
- Watch-outs: higher upfront and ongoing cost, and you need people who can run it.
- Typical fit: organizations with strict data residency rules, legacy systems that are hard to move, or very steady, predictable workloads.
Hybrid cloud
Hybrid cloud connects a private environment with one or more public clouds so data and applications can move between them. A hospital might keep patient records in a private environment while running its appointment app on a public cloud.
It is the most common real-world pattern. Flexera’s 2025 State of the Cloud report found that 70% of respondents embrace hybrid strategies, with data and apps in at least one public and one private cloud. The hard part is not choosing hybrid. It is keeping data and applications portable and consistent across both sides.
Multi-cloud
Multi-cloud means using public cloud services from more than one provider. Organizations do this to reach specialized services, avoid depending on a single vendor, or meet regional requirements. According to the same Flexera report, companies use 2.4 public cloud providers on average.
The trade-off is complexity. Analysts summarizing the report note that multi-cloud widens the security surface and the skills gap, which can cancel out the agility you were after if your team is not ready. Hybrid and multi-cloud are not opposites. A company can be both.
Community cloud
NIST also describes a community cloud, shared by several organizations with common concerns such as a mission, security needs or compliance rules. It is less common, but you will meet it in government, research and some healthcare consortia.
Cloud Service Models: How Much Do You Manage?
Service models sit on top of any deployment model. The question is how much of the technology stack the provider runs for you.
IaaS: infrastructure as a service
The provider supplies virtual machines, storage and networking. You install and manage the operating system, runtime, applications and data.
- You get: the most control and flexibility.
- You manage: nearly everything above the hardware, including patching and scaling configuration.
- Good for: custom architectures, migrating existing servers, data platforms and teams with strong operations skills.
PaaS: platform as a service
The provider also manages the operating system and runtime environment. You deploy code and data, and the platform handles servers, scaling and much of the plumbing.
- You get: faster development with less operational work.
- You manage: your application and its data.
- Good for: developers building web apps, APIs and mobile backends who want to ship quickly.
SaaS: software as a service
You use a finished application through a browser or app, such as email, a CRM or accounting software. The provider runs everything, and you configure settings and manage users.
- You get: the quickest path to value with almost no technical overhead.
- You manage: user access, your data and how you configure the tool.
- Good for: standard business functions where customization is not a competitive advantage.
Serverless
Many guides now list serverless computing as a fourth service model. You write small functions that run only when triggered, and you pay per execution. It suits event-driven jobs such as processing an uploaded file or reacting to a payment event.
Analogy: IaaS is renting an empty building and furnishing it yourself. PaaS is renting a furnished kitchen where you just cook. SaaS is ordering a meal from a restaurant. Serverless is a catering service that shows up only when guests arrive.
Side-by-Side Comparison of Cloud Computing Types
Use these tables to see the differences at a glance.
Deployment models
| Model | Who uses the environment | Control | Cost pattern | Best for |
|---|---|---|---|---|
| Public | Many customers, shared pool | Lower | Pay as you go, low entry cost | Startups, variable traffic, testing |
| Private | One organization | Highest | Higher fixed cost | Strict compliance, steady workloads |
| Hybrid | Private plus public, connected | High where needed | Mixed | Regulated data with flexible front ends |
| Multi-cloud | Several public providers | Varies | Mixed, harder to forecast | Avoiding lock-in, specialized services |
Service models
| Model | Provider manages | You manage | Typical user |
|---|---|---|---|
| IaaS | Hardware, virtualization, network | OS, runtime, apps, data | Infrastructure and DevOps teams |
| PaaS | Hardware plus OS and runtime | Apps and data | Software developers |
| SaaS | Everything | Users, settings, data | Business teams and end users |
| Serverless | Servers and scaling | Function code | Developers building event-driven features |
The key difference is control versus convenience. As you move from IaaS toward SaaS, you give up control and gain speed and simplicity.
Benefits and Challenges of Cloud Computing
Cost
The benefit is clear: you swap large capital purchases for usage-based spending, and you can shut off what you don’t use. The challenge is that flexible spending is easy to lose track of. Flexera reports that 84% of organizations say managing cloud spend is their top challenge, and budgets often overshoot targets by 17% because of weak forecasting. The same report shows wasted spend falling from 32% to 27% over four years as financial management practices mature.
Treat cost as a design decision, not a cleanup task. Our guide on AWS cost optimization in three phases shows how engineering and finance teams can work together on it, and the principles apply to any public cloud.
Security
Big providers invest heavily in physical and infrastructure security, which many small companies could not match alone. But the cloud adds risks of its own: misconfigured storage, weak identity controls and a larger surface area when you run several providers. Security does not come with the subscription. You have to design it, and monitor it. For one approach to the network side, see our piece on security as a service.
Scalability
Elasticity is the headline benefit of any cloud computing system. A retail app can absorb a holiday traffic spike and then shrink back. The catch is that applications must be built to scale. Lifting an old, rigid application onto cloud servers gives you a new bill, not new elasticity.
Compliance
This is where beginners get caught most often. The assumption is that moving to the cloud moves the responsibility. It doesn’t. The FFIEC IT Examination Handbook, written for financial institutions, says management must understand the shared responsibilities that come with the service and deployment model it uses. The more of the stack you manage (IaaS), the more you own. Even with SaaS, you remain accountable for your data and who can access it.
If you handle health data, payment data or personal data, talk with a compliance specialist or counsel familiar with HIPAA, PCI DSS or your state’s privacy laws before you pick a model. Do it before the migration, not after an audit.
Real-World Use Cases
These examples show how the models combine in practice.
- Startup launching an app: public cloud with PaaS or serverless. The team avoids hardware costs and ships quickly, then adds more control as the product matures.
- Hospital or clinic network: hybrid cloud. Sensitive records stay in a tightly controlled environment, while scheduling, telehealth and patient-facing apps scale in a public cloud. Our healthcare software work often starts with this split.
- Payments or wealth platform: hybrid or private for core ledgers and regulated data, public cloud for analytics and customer interfaces. The fintech industry page explains how we approach regulated rails.
- Online marketplace: public cloud IaaS and PaaS, because traffic is spiky and the architecture needs to flex around seasons and promotions.
- Data and AI teams: public cloud for elastic compute, often with a managed data warehouse. Our data engineering services cover the pipelines behind this.
- Small business back office: SaaS for email, accounting and CRM. No servers, no maintenance.
How to Choose the Right Cloud Model
A good choice starts with your needs, not the technology. Work through these steps in order.
- List your workloads. Separate what is customer-facing, what holds sensitive data and what is experimental. They rarely need the same model.
- Identify your rules. Note the regulations, contracts and data location requirements that apply. These can rule options out before cost even comes up.
- Be honest about your skills. IaaS and multi-cloud demand strong operations and security talent. If you lack it, favor PaaS or SaaS or bring in experienced engineers.
- Estimate demand. Steady, predictable usage can justify private capacity. Spiky or unknown usage points to public cloud.
- Plan for cost visibility. Decide who watches spend, how you tag resources and how often you review it.
- Think about exit and portability. Using code to define your environment keeps you flexible. Our overview of infrastructure as code tools is a good place to start.
- Start small and migrate in stages. Move one workload, measure, then continue. The cloud migration tooling guide helps you avoid surprise data-transfer and replication bills.
Analogy: choosing a cloud model without analyzing your workload is like buying a Ferrari for a farm. It’s impressive, expensive and wrong for the job.
Our Perspective: Pick the Simplest Model That Meets Your Rules
We build software for healthcare, fintech, marketplaces, ed-tech and AI companies, and the same pattern shows up again and again. Teams ask which cloud is best, when the better question is which responsibilities they are ready to own.
Our view is simple. Take the most managed option that still satisfies your compliance and performance needs. Use PaaS before IaaS, and SaaS before custom builds, when the function isn’t a differentiator. Add hybrid or multi-cloud when a clear requirement demands it, not because it sounds mature. Every extra environment adds identity, networking and monitoring work, and that work needs senior people.
That is why every Bitrupt engagement is staffed with senior engineers only. Architecture choices made in the first weeks decide your cost and security posture for years, and they are expensive to reverse.
— Usama
Getting Help With Your Cloud Move
If you want an experienced team to plan or run the move, our cloud migration services cover assessment, architecture and execution. We can also support you through enterprise software work or add senior engineers to your own team. Contact us and we will tell you plainly which model fits, and which one doesn’t.
Conclusion
Choosing a cloud computing system comes down to two decisions: where it runs (public, private, hybrid or multi-cloud) and how much you manage (IaaS, PaaS, SaaS or serverless). Most organizations end up combining several, so the real skill is managing cost, security and compliance across them. Remember that responsibility is shared, never fully transferred.
If you are weighing your options, speak with a cloud expert before you commit. A short architecture review now is far cheaper than rebuilding later. Reach out to our team and we will help you map your workloads to the right model.
FAQ
What are the main types of cloud computing?
There are two ways to classify them. Deployment models are public, private, hybrid and multi-cloud. Service models are IaaS, PaaS and SaaS, with serverless often added as a fourth. You combine one of each, for example a hybrid deployment that uses IaaS for core systems and SaaS for business tools.
What is the difference between IaaS, PaaS and SaaS?
The difference is how much you manage. With IaaS you manage the operating system, applications and data on rented infrastructure. With PaaS you manage only your application and data. With SaaS you simply use finished software and manage users and settings.
Is hybrid cloud better than public cloud?
Neither is better in general. Public cloud is faster and cheaper to start, while hybrid adds control for sensitive or regulated data. Hybrid is common, with 70% of surveyed organizations using it, but it also adds integration work.
Who is responsible for security in the cloud?
Both you and the provider, under what is called the shared responsibility model. The provider secures the underlying infrastructure, and you secure your applications, identities and data. The exact split depends on the service model, so confirm it in writing and ask your compliance advisor to review it.
What is the difference between hybrid cloud and multi-cloud?
Hybrid cloud mixes private and public environments. Multi-cloud uses several public cloud providers. They can overlap: a company with a private cloud and two public providers is running both.
Sources
- NIST SP 800-145, The NIST Definition of Cloud Computing
- Flexera 2025 State of the Cloud Report
- Making sense of multi-cloud: Flexera 2025 State of the Cloud Recap
- 84% of organizations struggle to manage cloud spend, Flexera
- FFIEC IT Examination Handbook, VII.A.4 Shared Responsibilities
