| Quick Answer — SaaS vs PaaS vs IaaS
The three main cloud service models differ by how much control and responsibility you take on. SaaS (Software as a Service) delivers ready-to-use applications — like Microsoft 365 or Xero — with no infrastructure management required. PaaS (Platform as a Service) provides a development environment so your team can build custom applications without managing underlying servers. IaaS (Infrastructure as a Service) gives you virtualised computing, storage, and networking resources with maximum control over the technology stack. Most Australian SMBs rely on SaaS for everyday tools, use IaaS for workload migrations, and consider PaaS when building custom software. |
Cloud computing has permanently changed how Australian businesses manage IT. Whether you’re a 20-person accounting firm in Melbourne or a 200-person manufacturing business in Brisbane, the shift to cloud services is well underway. Australia’s cloud computing market reached USD $12.7 billion in 2024 and is forecast to grow to USD $30.3 billion by 2033 a compound annual growth rate of over 10%. 12 reasons why cloud computing is important for Australian businesses goes deeper on why this shift is accelerating across every industry sector.But more cloud does not automatically mean better cloud.
Understanding the pros and cons of cloud computing before selecting a model helps you avoid the most common and costly mistakes overpaying, under-protecting your data, or locking into the wrong architecture for your workloads.
This guide breaks down each cloud service model in plain language, compares them across the metrics that matter for Australian SMBs, and gives you a clear decision framework. If you want expert guidance tailored to your situation, Hyetech offers managed cloud computing solutions designed specifically for Australian businesses.
What Are the Three Cloud Service Models?
Cloud services are divided into three delivery models, each representing a different level of abstraction how much of the technology stack the provider manages versus what you manage yourself. Think of it as a spectrum from maximum control to maximum convenience. For a broader overview of how these models relate to deployment types, see our guide to types of cloud computing.
IaaS — Infrastructure as a Service
IaaS provides virtualised computing infrastructure servers, storage, networking, and data centres delivered over the internet on a pay-as-you-go basis. You manage everything above the hardware level, including the operating system, middleware, runtime, and your applications.
With IaaS, the cloud provider owns and maintains the physical data centres; you rent virtual resources from them. This gives you the flexibility and control of owning your own servers without the capital expense and ongoing maintenance.
Common IaaS providers: Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform (GCP), Rackspace.
Australian business examples: A law firm migrating its on-premises file servers to Azure Virtual Machines. A financial services business using AWS to run compliance workloads in Australian data centres for data sovereignty. See our top cloud computing services in Australia for a full provider comparison.
PaaS — Platform as a Service
PaaS provides a managed development and deployment environment in the cloud. The provider handles the infrastructure (servers, storage, networking) and the platform layer (operating system, runtime, middleware), so your developers can focus entirely on writing and deploying applications.
PaaS sits in the middle of the stack. You bring the application code; the provider manages everything else. It dramatically accelerates software development because teams aren’t spending time provisioning and patching servers.
Common PaaS providers: Microsoft Azure App Service, Google App Engine, AWS Elastic Beanstalk, Heroku, Salesforce Platform.
Australian business examples: A retail chain building a custom customer portal on Azure App Service. An agri-tech company deploying a sensor data pipeline without managing the underlying server fleet.
SaaS — Software as a Service
SaaS delivers complete, ready-to-use software applications over the internet on a subscription basis. The provider manages everything infrastructure, platform, application, data storage, and updates. You simply log in and use the product.
SaaS is by far the most familiar cloud model for business users. If you use Microsoft 365, Xero, Google Workspace, Salesforce, or Dropbox, you’re already a SaaS customer. There is no installation, no patching, and no server to worry about.
Common SaaS applications: Microsoft 365, Google Workspace, Xero, MYOB AccountRight, Salesforce, HubSpot, Slack, Zoom.
Australian business examples: A professional services firm running Microsoft 365 for email, Teams, and document management. An SMB using Xero for accounting and Deputy for workforce management both SaaS applications requiring zero infrastructure management.
SaaS vs PaaS vs IaaS: Side-by-Side Comparison
The table below compares the three models across the dimensions that matter most for Australian SMBs:
| IaaS | PaaS | SaaS | |
| Control Level | Full (OS, middleware, apps) | Platform & apps | Apps only |
| IT Management | High — your team manages OS+ | Medium — platform managed | Low — vendor managed |
| Customisation | Maximum flexibility | Build custom apps | Limited to app config |
| Time to Deploy | Weeks (setup & config) | Days to weeks | Hours |
| Upfront Cost | Low (pay-as-you-go) | Low–medium | Low (subscription) |
| Ongoing IT Effort | Highest | Medium | Lowest |
| Best For | Custom infra, workload migration | Developers, custom apps | Business tools, productivity |
| AU Examples | AWS EC2, Azure VMs | Azure App Service, Google App Engine | Microsoft 365, Xero, Salesforce |
| Shared Responsibility | Infra managed by cloud; OS+ by you | OS & infra managed; code by you | Fully managed by vendor |
Understanding the Shared Responsibility Model
One of the most important and most misunderstood aspects of cloud computing is the shared responsibility model. In every cloud arrangement, the provider and the customer share security and compliance responsibilities. The split depends on which model you’re using. Understanding this distinction is the foundation of cloud security vs cybersecurity two related but distinct disciplines.
- IaaS: The provider secures physical infrastructure and network. You are responsible for patching operating systems, securing applications, configuring firewalls, and managing identity and access
- PaaS: The provider manages infrastructure and platform layer. You are responsible for securing your application code, data, and user access
- SaaS: The provider manages nearly everything. You are responsible for user access management, data governance, and how your people use the application
This matters enormously for compliance under Australian frameworks such as the Privacy Act 1988 and the Australian Privacy Principles, the Notifiable Data Breaches (NDB) scheme, and APRA CPS 234. Regardless of which cloud model you use, responsibility for notifying affected parties in the event of an eligible data breach rests with your business, not the cloud provider.
A Hyetech cybersecurity assessment can map your shared responsibilities across every cloud platform you use, helping you close compliance gaps before they become regulatory problems.
What Does Each Model Cost? A Realistic View for SMBs
Cost is rarely as simple as the headline subscription price. You need to factor in management overhead, skilled staff requirements, and the total cost of operating your chosen model.
IaaS Costs
Pricing model: Pay-as-you-go for compute, storage, and network consumption.
Upfront cost: Low — no hardware purchases required.
Hidden costs: IaaS demands significant IT management effort. Without experienced staff or a managed services partner, costs can escalate quickly through misconfigured resources, over-provisioned environments, and idle compute left running.Before committing to IaaS, review 10 cloud migration challenges and how to tackle them — the cost surprises often appear mid-migration, not before it.
Right for: Businesses with in-house IT teams or a managed IT partner who can optimise consumption.
PaaS Costs
Pricing model: Typically based on compute hours, API calls, and data storage consumed by your applications.
Upfront cost: Low to medium — developer tooling and environment setup involved.
Hidden costs: Vendor lock-in risk if you build deeply into a proprietary platform. Re-platforming can be expensive if you need to switch providers later.
Right for: Businesses with software development capability or a development partner building custom applications.
SaaS Costs
Pricing model: Per-user or per-seat monthly or annual subscriptions.
Upfront cost: Very low — start using the software within hours.
Hidden costs: Subscription costs accumulate across many tools (“SaaS sprawl”). Overpaying for unused licences is a common issue. Data portability is limited if you decide to exit a platform.
Right for: Most SMBs — predictable, manageable costs with minimal IT overhead.
Globally, SMBs are projected to allocate more than half of their technology budgets to cloud services in 2025. This makes right-sizing your cloud spend more critical than ever. Whether you’re dealing with SaaS licence bloat or IaaS over-provisioning, our guide to cloud cost optimisation for Australian businesses covers every lever available to reduce your bill without cutting active workloads. For managed IT services vs in-house IT cost comparisons, that guide also addresses how outsourcing IT management reduces total IaaS operating costs significantly.
Which Cloud Model Is Right for Your Australian Business?
Choosing between SaaS, PaaS, and IaaS isn’t a single decision most businesses end up using a mix of all three. Our guide to how businesses choose cloud services in Australia explores the decision patterns of Australian SMBs in more detail. The framework below helps you identify the right starting point.
When in doubt about which provider to go with once you’ve chosen a model, our how to choose a cloud service provider guide walks through the evaluation criteria specific to the Australian market.
Choose SaaS if…
- You need business software quickly with no infrastructure setup (email, accounting, CRM, collaboration)
- Your team doesn’t include dedicated IT or development staff
- Predictable monthly subscription costs are important for budget planning
- You want automatic updates, patches, and vendor-managed uptime SLAs
- You’re a small business that needs enterprise-grade tools without enterprise-grade IT staff
Bottom line for Australian SMBs: SaaS should be the default starting point for most business software requirements. Tools like Microsoft 365, Xero, and industry-specific platforms deliver enormous productivity and compliance benefits with minimal IT overhead.
Choose PaaS if…
- Your business is developing custom software, internal tools, or customer-facing applications
- You want to accelerate developer productivity by eliminating infrastructure management
- You’re building AI, machine learning, or data analytics capabilities into your product
- Rapid iteration and deployment are competitive priorities for your engineering team
Bottom line for Australian SMBs: PaaS is primarily relevant for businesses with software development teams or those working with a development partner on custom applications. It’s less relevant for the typical SMB that primarily consumes software rather than builds it.
Choose IaaS if…
- You’re migrating existing on-premises workloads (servers, databases, legacy applications) to the cloud
- Your applications or data require specific configurations, operating systems, or compliance controls that SaaS can’t accommodate
- You need to host applications in Australian data centres for data sovereignty under the Privacy Act or industry regulations
- Your business has unpredictable or highly variable compute demands (e.g. seasonal spikes)
- You want maximum flexibility without replacing your existing IT architecture all at once
Bottom line for Australian SMBs: IaaS is most valuable during cloud migration projects or when compliance requirements demand precise control over data storage and security configurations. Without managed support, IaaS can be complex and expensive to operate correctly.
Using All Three Together
Many mature Australian businesses run a hybrid model: SaaS for productivity tools, IaaS for infrastructure workloads, and PaaS for custom application development. This is sometimes called a multi-cloud or hybrid cloud strategy. For a deeper dive into how these deployment types interact, see our public cloud vs private cloud vs hybrid cloud comparison.
For example, a professional services firm might run Microsoft 365 (SaaS) for collaboration, Azure Virtual Machines (IaaS) for legacy line-of-business applications, and Azure App Service (PaaS) for a custom client portal. Managing this mix effectively requires clear governance, a defined cloud computing strategy, and consistent security controls across all three layers including a robust cloud backup strategy that covers data across all environments.
Australian Compliance Considerations for Each Model
Privacy Act 1988 and the NDB Scheme
Any cloud model that stores or processes personal information about Australians must comply with the Australian Privacy Principles (APPs) under the Privacy Act 1988. The Notifiable Data Breaches (NDB) scheme requires businesses to notify the OAIC and affected individuals in the event of an eligible data breach regardless of whether the breach occurs in your SaaS application, PaaS environment, or IaaS infrastructure.
Knowing how to respond to a data breach is essential for every Australian business, regardless of which cloud model you operate in. Your response obligations under the NDB scheme apply from day one.
Key implication: Ensure your cloud provider’s data processing agreements (DPAs) include clear provisions for breach notification, data residency, and sub-processor disclosure.
Data Residency and Sovereignty
Some Australian industries — financial services, healthcare, legal, and government — have strict requirements that certain data must be stored on Australian soil. When selecting an IaaS or SaaS provider, confirm that Australian data centres are available and that your contract explicitly restricts data from being processed offshore.
Microsoft Azure, AWS, and Google Cloud all operate data centres in Australia, giving businesses the option to keep data onshore. IaaS typically offers the most explicit control over data residency.
APRA CPS 234 (Financial Services)
Financial services organisations regulated by APRA must meet information security requirements under CPS 234, including maintaining security capability proportional to threats, conducting regular security testing, and ensuring third-party providers (including cloud providers) meet equivalent security standards.
Whether you use SaaS, PaaS, or IaaS, your organisation retains accountability for your information security posture. Hyetech supports financial services clients with cybersecurity solutions aligned to APRA CPS 234 requirements.
Essential Eight and the ACSC
The ACSC Essential Eight is the widely adopted security baseline for Australian businesses. Cloud adoption doesn’t reduce your Essential Eight obligations some controls (patch management, MFA) become easier to implement in cloud environments, while others (application control, macro restrictions) require specific attention. Understanding what MFA is and why your business needs it is a practical starting point for meeting Essential Eight requirements across your SaaS and IaaS environments.
Common Mistakes Australian Businesses Make When Choosing a Cloud Model
- Assuming SaaS is always the safest choice: SaaS reduces infrastructure responsibility but doesn’t eliminate security obligations. Misconfigured access controls and lack of MFA in SaaS applications are leading causes of data breaches
- Underestimating the management overhead of IaaS: IaaS is not a “set and forget” solution. Unpatched VMs, misconfigured storage buckets, and overly permissive network rules are among the most common cloud security failures
- Over-committing to a single cloud vendor: Deep vendor lock-in limits flexibility and increases costs. Building a diversified cloud strategy with a managed services partner gives you more leverage and resilience
- Skipping a cloud security review: Moving to the cloud without a formal security assessment exposes your business to risks that are difficult and expensive to remediate after the fact
- Ignoring internet connectivity: Cloud performance depends heavily on your internet connection. A cloud strategy without robust business internet plans and telecommunications infrastructure can result in poor user experience, especially for IaaS and high-bandwidth SaaS applications
Frequently Asked Questions
What is the difference between SaaS, PaaS, and IaaS in simple terms?
Think of it as renting a property. IaaS is renting an empty block of land and building your own house. PaaS is renting a house that’s already built, where you choose the interior design. SaaS is renting a fully serviced apartment furnished, cleaned, and maintained; you just move in. The more managed the model, the less control you have but the less effort required to operate it.
Which cloud model is best for small businesses in Australia?
For most Australian small businesses, SaaS is the best starting point. As businesses grow and develop custom software requirements, PaaS becomes relevant. IaaS is most valuable when migrating from on-premises infrastructure or when compliance requirements demand precise data residency controls.
Is SaaS secure for Australian businesses?
SaaS can be highly secure, but security depends on both the provider’s controls and how your organisation configures and manages the application. Key security practices include enabling multi-factor authentication, managing user permissions on the principle of least privilege, and regularly reviewing active accounts.
Can I use more than one cloud model at the same time?
Yes — in fact, most businesses already do. Managing this complexity effectively — with consistent security policies, clear ownership, and cost governance is where a managed IT services provider adds the most value. A good ICT managed service provider will help you govern a multi-model cloud environment as a single, coherent strategy.
What is the difference between cloud models and cloud deployment types?
Cloud service models (SaaS, PaaS, IaaS) describe what is delivered to you. Cloud deployment types describe where it runs public, private, or hybrid cloud. Most SaaS products run on public cloud. IaaS and PaaS can run on public, private, or hybrid clouds depending on your requirements.
How Hyetech Helps Australian Businesses Navigate Cloud Decisions
Choosing between SaaS, PaaS, and IaaS is only the beginning. Making cloud work for your business securely, cost-effectively, and in compliance with Australian regulations requires a clear strategy, the right implementation, and ongoing management.
Hyetech is an Australian managed IT and cybersecurity provider and Microsoft Gold Certified Partner. We work with SMBs across Australia to design and deliver cloud strategies that fit their business requirements, compliance obligations, and budget. Our cloud services include:
- Cloud migration and infrastructure management across Microsoft Azure and AWS Microsoft 365 deployment, licensing optimisation, and security hardening
- Cybersecurity assessments and ongoing managed security aligned to the ACSC Essential Eight and APRA CPS 234
- Business internet plans and telecommunications solutions to ensure your cloud performance is reliable
- Hardware and software procurement to support your cloud and on-premises environments
Ready to Build a Cloud Strategy That Actually Works?
Whether you’re moving from on-premises to cloud for the first time, optimising an existing cloud environment, or trying to untangle a complex multi-cloud setup, Hyetech can help.
Contact our team for a no-obligation cloud assessment tailored to your Australian business.