SaaS is closely related to the ASP (application service provider) and on demand computing software delivery models. IDC identifies two slightly different delivery models for SaaS. The hosted application management (hosted AM) model is similar to ASP: a provider hosts commercially available software for customers and delivers it over the Web. In the software on demand model, the provider gives customers network-based access to a single copy of an application created specifically for SaaS distribution.
Benefits of the SaaS model include:
easier administration
automatic updates and patch management
compatibility: All users will have the same version of software.
easier collaboration, for the same reason
global accessibility.
The traditional model of software distribution, in which software is purchased for and installed on personal computers, is sometimes referred to as software as a product.