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).
Software as a service is a software licensing and deployment model where the software is licensed and centrally hosted on a subscription basis. It is sometimes called "optional software" and is previously called "software plus services" by Microsoft.
Software as a service (SaaS) is a software deployment model where a third-party provider hosts applications and provides them to customers over the Internet. SaaS is one of the three major cloud computing categories with infrastructure (IaaS) as a service and platform as a service (PaaS).
SaaS is closely associated with application service provider (ASP) and optional computing software deployment models. SaaS's hosted application management model is similar to the ASP that the provider provides to end-users who host the client's software and are approved over the internet.
In the SaaS model in the requested software, the provider provides network-based access to a single copy of the application that the customer creates, in particular the SaaS distribution.
The application's source code is the same for all customers and is available to all customers when new features or functionality are available. Depending on the service level agreement (SLA), the customer's data for each model can be stored locally, in the cloud, or locally and in the cloud. For example, a business can write its own software tools and use the SaaS provider's APIs to integrate these tools with the SaaS offer.