Software as a Service (or SaaS) enables cost reduction while upgrading service quality through cloud-based applications.
Software as a service (or SaaS) mode delivers an application over the Internet as a service. Instead of installing and maintaining software, you simply access the Internet, freeing yourself from the complex management of software and hardware.
SaaS applications run on a SaaS providers servers. The provider manages access to the application, including security, availability, and performance.
Software as a service allows the user easier access and use, and the service provider easier and faster maintenance, development and upgrade of software, which provides a great advantage over traditional software solutions.
Good examples of SaaS applications include Google Apps, Dropbox, and Salesforce