What is SaaS (Software-as-a-Service)?

Software-as-a-Service is a software distribution model in which a third-party provider hosts applications and makes them available over the internet. One of three main categories of cloud computing, a SaaS model system is managed entirely by a third-party provider.

How is Software as a Service (SaaS) different from Platform-as-a-Service (PaaS) and Infrastructure-as-a-Service (IaaS)?

While all three are cloud computing models that use the internet to deliver some or all of its services, the main difference lies in which services a provider manages and what a company manages. In the case of Software-as-a-Service (SaaS), a third-party provider manages all services that are part of the system.