What Are the 3 Main Cloud Computing Service Models? SaaS, PaaS, IaaS

| Author , tagged in cloud managed services
Cloudticity, L.L.C.

The three main cloud computing service models are Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). Each model has distinct characteristics that make it appropriate for addressing specific types of business objectives. Each cloud computing model offers cloud customers a varying degree of control and level of responsibility when configuring and securing a solution.

In this article, we’re going to take a close look at the differences between these three cloud computing models to help you to choose the right one to address your unique business objectives.

What is Cloud Computing?

Cloud computing is the delivery of computing services over the Internet. The services can include physical or virtual servers, storage, networking, and databases. Cloud computing also provides more abstract services such as access to analytical engines and business intelligence platforms.

Cloud service providers (CSPs) have developed cloud computing service models that provide different types of IT resources and support. Each model addresses a different set of problems a business needs to solve to be competitive in today’s market.

Why You Should Think About Moving to The Cloud

The market for cloud computing services continues to grow. Estimates expect the market size to  reach $1,614.1 billion by 2030. That’s 1.6 trillion dollars spent on cloud computing in a few years, representing a CAGR of over 17% from 2022 to 2030.

Businesses of all sizes and types are migrating some or all of their IT environment to the cloud to take advantage of the many benefits offered by CSPs. These benefits include:

  • Reduced capital expenditures and cost savings by using the resources of cloud providers;
  • Access to cutting-edge technology that would be difficult to implement in an on-premises data center;
  • Virtually limitless scalability that allows a business to grow and optimize its use of cloud resources;
  • Enhanced data availability as resources can be accessed from any Internet connection;
  • Experienced technical personnel to help implement cloud solutions.

What Are the Three Cloud Computing Service Delivery Models?

Let’s look at what differentiates the three main cloud computing service models. We’ll start by defining them and then discuss the advantages and disadvantages of each of the three cloud service models.

Infrastructure as a Service (IaaS)

In the IaaS model, the cloud provider supplies the customer with a customized infrastructure on which they can run any operating system or application. It’s the most flexible of the three cloud computing service models as it gives the customer almost total control of the infrastructure.

Advantages of IaaS

The advantages of an IaaS solution include:

  • Extensive flexibility and scalability;
  • Cost savings when compared to upgrading in-house resources;
  • Ease of deployment;
  • Allows companies to supplement in-house resources for specific projects.

Disadvantages of IaaS

An IaaS offering may pose disadvantages to customers including:

  • The need for technical staff to manage the infrastructure;
  • Potential security risks by giving up control to the CSP;
  • IaaS solutions may require substantial process changes;
  • Vendor lock-in can make it difficult to migrate to a different cloud provider.

Platform as a Service (PaaS)

The PaaS model provides customers with a virtualized application development platform without the need for them to furnish hardware or system administration using in-house resources. All necessary infrastructure components and application development services are provided and managed by the CSP.

Advantages of PaaS

Some of the advantages of the PaaS model are:

  • Cost savings;
  • Reduced development time-to-market;
  • Robust infrastructure security;
  • Access to cutting-edge technology to future-proof an organization;
  • Supports a remote workforce.

Disadvantages of PaaS

Possible disadvantages of PaaS include:

  • Compatibility with existing development environments;
  • Dependency on the CSP’s ability to perform.

Software as a Service (SaaS)

SaaS solutions offer customers direct, online access to applications without any of the challenges of maintaining them, their platform, or infrastructure. Customers are essentially end-users of the software delivered through the SaaS model.

Advantages of SaaS

Many advantages can be enjoyed with an SaaS offering including:

  • Accessibility to applications at any time from an Internet connection;
  • Reduced operational management;
  • Cost-effective with models that charge customers based on usage;
  • Easy scalability to address evolving business requirements;
  • Availability of cloud-based analytics and business intelligence solutions.

Disadvantages of SaaS

Disadvantages of an SaaS solution include:

  • Loss of customer control;
  • Potential network latency;
  • Limited customization options;

Choosing the Right Cloud Computing Model for Your Business

Each of the service models in cloud computing is designed to address a different set of business objectives or provide customers with innovative solutions to help them achieve their goals. An organization needs to choose the right model when opting for a cloud solution to effectively address its issues and obtain the maximum value from its investment.

When you should use IaaS

IaaS is a viable choice when a company needs additional computing power but does not want to upgrade its on-premises environment. Organizations often opt for an IaaS solution to upgrade their infrastructure quickly vs. buying hardware and scaling over the course of several months. IaaS infrastructure increases flexibility and scalability of infrastructure and also doesn’t require physical capacity like an on-premise model. In addition, leveraging IaaS allows you to gain access to cutting edge technologies as they are released.

When you should use PaaS

A PaaS solution is appropriate for companies that:

  • Need to shorten development cycles to address business requirements;
  • Require the ability to easily scale applications;
  • Have complex development projects requiring collaboration between remote teams.

When you should use SaaS

SaaS solutions are the easiest of the three service models of cloud computing to implement as they are primarily supported by the SaaS vendor. A SaaS offering should be used when a company:

  • Doesn’t have the resources to deploy an on-premises solution;
  • Needs to support a mobile workforce;
  • Requires a collaborative platform to further business objectives.

How Do You Secure Your Cloud Services?

Securing cloud resources is a responsibility shared by the CSP/vendor and the customer. Each party is responsible for the security of different aspects and components of a cloud offering. The degree of responsibility each party assumes is influenced by the choice of cloud computing service model used to implement a solution. Some vendors may implement a modified version of the shared responsibility matrix.

The following outline provides details on the security responsibility of a CSP and its customer.

Security for IaaS

Cloud provider:

  • Services and storage;
  • Network and virtualization layer;
  • Physical security of the data center.


  • Operating systems;
  • Software stack and applications;
  • Data resources.

Security for PaaS

Cloud provider:

  • Services and storage;
  • Network and virtualization layer;
  • Physical security of the data center
  • Operating systems;
  • Development tools.


  • Middleware;
  • Code and data generated on the platform.

Security for SaaS

Cloud provider:

  • The CSP assumes virtually all security functions for a SaaS solution.


  • Needs to secure login credentials to avoid unauthorized access to the software.

What to Expect From Cloud Computing in the Future

Cloud computing will continue to grow as more businesses take advantage of its benefits and CSPs develop innovative offerings to attract new customers. Familiarity with the three service models of cloud computing can help you align your business requirements with the appropriate infrastructure, platform, or software.

Businesses interested in these benefits and in optimizing their cloud investment should consider working with an experienced managed service provider (MSP) like  Cloudticity. Cloudticity brings a wealth of experience in helping healthcare businesses identify and implement the right solution to address their needs. Partnering with Cloudticity is an excellent first step toward maximizing the value of cloud computing for your business.

To learn more about how you can make the most of your cloud investment, read the white paper Maximize Cloud Value for Health Tech. Or schedule a free consultation to learn how we can partner together for your cloud transformation.


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