The authors believe that SaaS (Software as a Service) is going to have a major impact on the software industry. SaaS will change the way people build, sell, buy, and use software. The concept behind software as a service is simple. Instead of a software vendor selling a software license that the client then implements and maintains in its own environment, the vendor – or, more properly, the service provider – hosts the application on its own computer in its own data center and provides access to the system over the internet on a subscription basis. For the SaaS model to be put into effect, the vendor will need to evaluate its traditional application.