Cloud computing has been transformative as it enables organizations of all sizes to keep up with consumer demand, and helps smaller companies compete with large enterprises. Your organization stands to gain significantly from migrating to a cloud solution. But which cloud computing delivery service model is right for you?  

This blog focuses on the three primary types of cloud computing service delivery models and how you can use them. 

What Are the Three Cloud Computing Service Delivery Models? 

Maximizing the value derived from your cloud service is crucial, and concurrently safeguarding your assets from potential threats is paramount. To achieve this, it is imperative to comprehend the functionality of each cloud computing service delivery model. Additionally, a thorough understanding of the Shared Security Responsibility Model associated with each model is essential. Ultimately, selecting the model that aligns most effectively with your business objectives is the key to a successful and secure cloud computing strategy.

There are three main cloud service delivery models: 

  • Software as a Service (SaaS)
  • Infrastructure as a Service (IaaS)
  • Platform as a Service (PaaS)

While all of them are powered by cloud computing, each model operates uniquely, offering organizations a wide array of distinct services.

Software as a Service

SaaS is the most well-known of the three cloud service delivery models. That’s because most people use SaaS applications every day, whether they know it or not. When people talk about “the cloud,” they usually mean SaaS applications like Google Drive, Dropbox, or Netflix.  

The SaaS delivery model enables users to utilize fully functional software that is operated and managed in the cloud. Typically, users access SaaS applications through a web browser. The key advantage to this is the elimination of concerns related to downloading and installing programs, as these tasks are handled by the vendor. However, depending on the specific service, you may need to download a plugin.

Key benefits of SaaS include:

It’s lightweight

Running SaaS applications typically doesn’t require as many computing resources as on-premises software.

No need for software updates

Vendors manage and update SaaS applications. That means everyone has access to the most up-to-date version at all times.

No more software licensing

Premium SaaS applications adhere to the subscription model, eliminating the need to purchase and regularly renew software licenses. This approach is particularly favored by businesses employing remote workers, as it enables them to leverage robust business tools without the necessity for hardware upgrades or manual software updates.

Infrastructure as a Service (IaaS)

Historically, a company’s IT infrastructure was stored on-premises. This meant organizations had to constantly invest in expensive hardware and ensure everything stayed up to date.  

As technology advanced, companies increasingly relied on cloud service providers to streamline the management of their IT infrastructure. This shift led to the emergence of Infrastructure as a Service (IaaS), prompting organizations to migrate from on-premises to cloud-based infrastructure. IaaS empowers businesses by providing access to virtualized computing resources hosted on cloud servers.

IaaS benefits include:

Greater flexibility

IaaS lets you access infrastructure services on demand. You can scale infrastructure to support business growth and reduce it when needed.

Cost savings

You don’t have to buy physical hardware every time you want to upgrade. As your computing infrastructure is provided on a subscription basis, your vendor is the one responsible for infrastructure management.


Your assets are stored in a remote data center, where it’s managed by cloud service providers. This service model all but eliminates the threat of a single point of failure. 

Infrastructure as a Service (IaaS) eradicates the necessity for in-house hardware, allowing organizations to access cutting-edge IT infrastructure at a significantly reduced cost. This renders IaaS an increasingly favored service model, particularly among small and medium-sized companies. By eliminating the need for substantial hardware investments, IaaS facilitates a more equitable competitive landscape, enabling smaller enterprises to rival larger organizations with more extensive budgets. Additionally, the flexibility to scale infrastructure on demand further enhances the appeal of IaaS for businesses of varying sizes.

Platform as a Service (PaaS)

This cloud computing service delivery model is commonly referred to as a solution stack. It empowers organizations to develop, execute, and oversee cloud-based software without the necessity for onsite infrastructure. These platforms are supplied and maintained by a third-party vendor, relieving businesses of concerns related to tasks such as backups and server provisioning—all of which are handled on their behalf.

PaaS benefits include:

Improved efficiency

Since a third party handles your IT infrastructure needs, businesses can spend more time focusing on developing, testing, and deploying applications. 


PaaS gives businesses a platform with development tools, so they can develop, test, and host applications in the same environment. 

Better collaboration

PaaS requires teams to develop over the internet, eliminating the need to transfer files and manually sync data. Everyone works with the same up-to-date information all the time. 

Which Cloud Computing Service Delivery Model Is Right for You? 

There are many things to consider when adopting cloud technology. You want to ensure the model you choose is cost effective and capable of helping you meet your organization’s demands.  

All three cloud models provide businesses with an excellent alternative to on-premises solutions. For an overview of the differences of on-prem vs. cloud, read On-Premises vs. Cloud: What’s the Difference? When it comes to cloud, each cloud computing model comes with its benefits and drawbacks. Choosing the right option for your organization depends largely on your needs and what you hope to gain from migrating to cloud services.  

When to choose SaaS 

SaaS is the best model for companies that need applications, but don’t need to develop an up-to-date infrastructure. As such, this makes SaaS a great excellent solution for small and medium-sized businesses that: 

  • Need to support remote work 
  • Frequently require teams to collaborate 
  • Don’t have the resources or need to deploy on-premises hardware 

Keep in mind that SaaS prioritizes configuration over customization.

Many organizations have on-prem software solutions customized (or developed) to suit their unique business needs. But this isn’t an approach commonly associated with SaaS.  

Most vendors develop SaaS applications with an objective of serving as many customers as they can. While you can configure these applications to suit your needs, you probably won’t be able to customize them if you need a one-of-a-kind software solution.  

When to choose IaaS 

If your organization requires more computing power but you don’t have the time or resources to upgrade your on-premises IT infrastructure, IaaS can help. What are some reasons why you might need IaaS? Consider it if you need: 

  • Rapid deployment and/or reduction of infrastructure based on your business performance
  • Access to greater computing power to pursue your digital strategies, but you don’t want to own the infrastructure  
  • A solution so you don’t have to bring on IT personnel to manage your infrastructure 

After choosing an IaaS vendor, you need to decide which type of service model you want: 

  • private cloud that’s used exclusively by your organization. 
  • public cloud that’s used by multiple organizations. 
  • A hybrid cloud that uses both public and private infrastructure. 

There are many differences between the types of service models. Here are some pros and cons of each: 

  • Private cloud offers companies more flexibility and control over their infrastructure, but it’s more expensive.
  • Public cloud is cheaper and provides customers powerful computing power, but organizations have less control over their configurations.
  • Hybrid cloud offers the best of both worlds, but it can be significantly more challenging to implement and maintain.  

Certain organizations choose to utilize a private cloud primarily due to security considerations. This does not imply that the public cloud lacks security; rather, the method of accessing the cloud environment differs fundamentally. The private cloud is accessed through private network links, in contrast to the public cloud, which lacks this private network access.

When to choose PaaS 

If your organization requires a flexible computing platform for developing and testing applications and software, PaaS is your best bet. Whether your company specializes in software development or simply implements agile methodologies, PaaS can help.  

PaaS gives you the tools to quickly build, test, and deploy applications so you can develop iteratively and modify software based on customer feedback. Here are some reasons why you may want to implement PaaS: 

  • You have projects requiring collaboration with multiple developers. 
  • Your business model requires you to have shorter development cycles. 
  • You need a solution that enables you to scale your applications as needed, without putting a strain on internal resources. 

Be mindful of vendor lock-in when choosing a PaaS provider. Most providers have their own configuration requirements, which can make it challenging to migrate from one platform to another. 

How Do You Secure Your Cloud Computing Services? 

Whether you opt for SaaS, PaaS, or IaaS, a comprehensive cloud security strategy is essential to safeguard your assets. Unfortunately, there is no universal security solution applicable to all cloud services. Each model operates distinctively, requiring careful consideration when devising a security strategy. According to the Cloud (In)Security Report, a staggering 98.6% of organizations experience misconfigurations in their cloud environments.

Security for SaaS

SaaS providers are responsible for ensuring the security of their cloud services. This means you don’t have to worry about finding and correcting security vulnerabilities within the SaaS application your provider will handle that.  

But that doesn’t mean you don’t have to factor SaaS into your security strategy. You could still fall victim to a data breach if an unauthorized party accessed your account. Here are some SaaS security practices to minimize your threat risk: 

  • Implement single sign-on (SSO) capabilities so you can easily authorize and revoke employee accounts when needed. 
  • Ensure employees only have access to resources they need to complete their jobs. Revoke access when they no longer need those privileges. 
  • Make sure your SaaS providers have a good track record with security, follow applicable compliance regulations, and include end-to-end encryption in their services. 

SaaS security starts with you. Make sure your organization has systems and policies in place to promote good security practices. Things like multifactor authentication (MFA) and a strong password policy go a long way in protecting your data from cyberattacks. 

Security for IaaS 

IaaS follows the shared security responsibility model. This model requires the cloud service provider to secure the cloud infrastructure and the customer secures everything built on top of that infrastructure. Here are some best security practices for IaaS: 

  • Maintain up-to-date systems to keep your cloud infrastructure protected against security threats.  
  • Conduct privilege audits to ensure everyone has access to what they need to complete their tasks — and nothing more. 
  • Actively scan for security vulnerabilities that malicious parties could exploit. 
  • Identity and correct threats using deep packet detection or intrusion detection systems. 

One of the most important parts of securing IaaS is fixing misconfigurations. As the customer, it’s your responsibility to detect those misconfigurations and prevent them from growing into bigger problems. 

Security for PaaS 

PaaS also follows the shared security responsibility model. This means you’re responsible for ensuring the security within your cloud software apps — not your service provider. Some PaaS security best practices include: 

  • Use real-time protection solutions that can detect and block attacks. Most PaaS platforms come with a range of native security tools and add-ons you can use to protect your cloud applications. 
  • Routinely scan your applications and libraries for vulnerabilities and threats. 
  • During your development lifecycle, consistently analyze your code for potential vulnerabilities. 
  • Strengthen your security posture and regulatory compliance by using a tool for collecting and analyzing logs. 

Because you use PaaS to develop software, it’s important you have security baked into your development process. Teams always must consider security and compliance implications when developing and launching software. 

Choosing the Right Cloud Computing Service Delivery Models

Successful cloud migration is achievable with the right approach. Once you have a clear understanding of your company’s needs and strategic goals, selecting a model that aligns with your business objectives and brings value to your organization becomes straightforward.

Whether you are utilizing cloud services to develop software or expand your infrastructure, ensuring continuous and robust security is essential. This is where Fortra’s Alert Logic Managed Detection and Response (MDR) comes into play. Our solution offers round-the-clock protection against potential threats. By leveraging this advanced security solution, you not only safeguard your systems from attackers but also ensure ongoing compliance and proactively address security incidents before they escalate into major issues.

Angelica Villarreal
About the Author
Angelica Villarreal
Angelica Villarreal is a product marketing expert at Fortra’s Alert Logic. She brings over 15 years’ experience in security, with expertise in cloud, MDR/XDR, data protection, and IT infrastructure.

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