SaaS, PaaS, and IaaS are three general terms that describe different types of service-based computing. In each case, companies use IT resources on demand from external cloud providers rather than purchasing physical assets such as hardware equipment and software licenses. The one-service model maximizes efficiency so it can be more cost-effective than traditional options.
Organizations pay only for what they use, making it easier to distribute and predict costs. New resources can be provisioned whenever they are needed, enabling rapid scaling in response to new business needs.
While SaaS, PaaS, and IaaS all share these benefits, each targets different use cases and user groups. In this post, we’ll look at how the three offerings slot into your tech stack and when you should choose one over the other.
SaaS: Software as a Service
SaaS (Software as a Service) is the most commonly used of these terms It refers to the complete software that can be used in exchange for a recurring subscription fee. These products are typically hosted in the cloud and accessed from a web browser or mobile device. The term can also refer to licensed desktop software, such as paying for Microsoft Office programs through a Microsoft 365 plan.
Some of the more popular SaaS applications include Slack for messaging, GitHub for code hosting, and Stripe for payment billing. Each of these gives you a ready-to-use platform that solves a specific problem for you.
SaaS solutions are usually delivered continuously so that they improve their lives. As part of an ongoing subscription, new features, and security patches are delivered at a regular cadence, without requiring action from the end user.
Most SaaS providers offer different payment tiers that allow you to select the combination of features you need. Additional users, storage quotas, and add-on modules can be purchased instead of paying for everything upfront when needed.
PaaS: Platform as a Service
PaaS is a complete platform as a service. Unlike SaaS, PaaS offerings are not targeted to software end users. These are tools that development teams use to create, deploy, and maintain applications. PaaS solutions eliminate infrastructure provisioning and ongoing complexity. Developers used to manually set up the server by configuring the operating system, installing the runtime environment of their programming language, and configuring admin tasks such as backup and monitoring.
PaaS services like Heroku and Firebase handle these tasks for you. They provide a ready-to-use environment that allows you to automatically deploy code every time you make a change. The PaaS provider identifies your project’s source language, provides an appropriate runtime, and exposes your service to the Internet.
Using a PaaS can provide busy DevOps teams with significant time and cost savings. They are quick and easy to deploy, offer built-in scalability, and are generally easier to manage than self-hosted infrastructure. Most PaaS platforms have a graphical control panel that allows you to monitor deployed apps and roll back problematic changes.
IaaS: Infrastructure as a Service
Infrastructure as a Service (IaaS) describes the on-demand provisioning of new cloud computing components. Virtual servers are the most common form of IaaS but private networks, load balancers, and object storage systems can also fall under this heading. All major cloud providers such as AWS, Azure, Google Cloud, and DigitalOcean have established IaaS solutions.
Resources deployed from an IaaS provider are typically served using one of two models: shared or dedicated hosting. Shared hosting means multiple virtual computing resources owned by multiple customers supported by the same physical hardware. It’s more cost-effective but can hurt performance if you’ve got “noisy neighbors”. Dedicated hosting gives you exclusive use of a specific physical resource. This is similar to locating your own server in a cloud provider’s data center.
Infrastructure as a Service lowers costs and offers greater flexibility than traditional on-premises servers. You are free to scale your resources up and down to satisfy changing customer demands and new product launches. You’re in control of the virtual servers you provide so you can choose the operating system, install the packages you need, and fine-tune settings for maximum performance and reliability.
SaaS vs. PaaS vs. IaaS: Which Should You Use?
SaaS, PaaS, and IaaS each address a unique aspect of cloud computing. If you’re looking for new software to help run your business, a Software as a Service (SaaS) platform is what you should be looking for. Products marketed using this term are ready-to-use solutions you can license on an ongoing basis. PaaS and IaaS are more technical options that target developers and engineering teams. These solutions allow you to build and deliver your own SaaS products. Where they differ is in the level of control they offer.
A Platform as a Service (PaaS) lets you outsource your infrastructure so you can focus on the functionality of your applications. These solutions automatically generate your code and deploy it to a suitably configured environment. They can help you bring new products to market faster while reducing the maintenance burden over time. However, PaaS approaches can prove to limit in the long run as you are locked into the features of your chosen platform.
Infrastructure as a Service (IaaS) gives you full control over your computing resources. You can provision and manage your own infrastructure elements while benefiting from the scaling options of cloud services.
The tradeoff is a greater maintenance burden because you will be responsible for configuring and maintaining each system as if it were a physical machine located on your premises. PaaS is generally the best choice for companies building simple SaaS solutions where rapid code releases are a top priority. IaaS is a good fit for organizations that already manage their own tooling and want the highest degree of control over their environment.
Conclusion
SaaS, PaaS, and IaaS are variants of cloud computing that allow you to buy resources on a rolling service basis. This is often more flexible and cost-effective than buying or licensing equipment outright.
The three models are not mutually exclusive. Businesses can use them alongside each other: dedicated servers can be hosted on an IaaS platform and application deployments can target a PaaS solution, while administrative tasks such as payroll, project management, and HR are handled through third-party SaaS products.
Understanding the respective focus areas of SaaS, PaaS, and IaaS will help you select the best technology for each new situation. Mixing and matching can be the most efficient purchasing method, allowing you to enjoy the benefits of all three with minimal drawbacks. While IaaS and PaaS help delivers software solutions, SaaS is something that organizations can both consume and produce.
