What is Software as a Service (SaaS)?

One of the most popular forms of cloud computing is software as a service (SaaS). It is one of the three major categories of cloud computing, along with infrastructure as a service (IaaS) and platform as a service (PaaS). SaaS has become the dominant software delivery model since the concept debuted in the early 2000s.

SaaS defined

SaaS stands for software as a service, which means software is hosted by a third-party provider and delivered to customers over the internet as a service. While most SaaS products are aimed at business users, some products have proved popular with individual consumers, like note-taking app Evernote or personal finance tools like TurboTax and Mint.

In business settings, users access productivity applications or enterprise software from a service provider instead of from their company’s private data center. Microsoft 365 and Salesforce are common examples of such SaaS software used in business that had been previously hosted and distributed by businesses’ own data centers.

SaaS is a marked difference to the old model of making a one-off purchase of software that must be hosted, implemented, and maintained by the buyers themselves.

The SaaS delivery model is enabled by a multitenant architecture, where a service provider can distribute multiple versions of the same software from a single physical server. Each user or business has its own version of the application, with the associated customizations, data, and access controls, but from a shared code base that can be patched, updated, and maintained centrally.