Software as a Service (SaaS)

Software as a service (SaaS) is a software distribution model in which a third-party provider hosts applications and makes them available to customers over the Internet. SaaS is one of three main categories of cloud computing, alongside infrastructure as a service (IaaS) and platform as a service (PaaS).

SaaS is closely related to the application service provider (ASP) and on demand computing software delivery models. The hosted application management model of SaaS is similar to ASP, where the provider hosts the customer’s software and delivers it to approved end users over the internet. In the software on demand SaaS model, the provider gives customers network-based access to a single copy of an application that the provider created specifically for SaaS distribution. The application’s source code is the same for all customers and when new features or functionalities are rolled out, they are rolled out to all customers. Depending upon the service level agreement (SLA), the customer’s data for each model may be stored locally, in the cloud or both locally and in the cloud.Organizations can integrate SaaS applications with other software using application programming interfaces (APIs). For example, a business can write its own software tools and use the SaaS provider’s APIs to integrate those tools with the SaaS offering.