Software as a Service (SaaS) is a cloud based service where instead of downloading software you instead access an application via an web browser to run and update it. SaaS is the largest cloud market of today and is still growing fast. SaaS eliminates the requirement to install and run applications to computers one by one thanks to its software distribution model. SaaS is closely related to the application service provider (ASP) and on demand computing software delivery models. In the software on demand SaaS model, the provider gives customers network-based access to a single copy of an application that the provider created specifically for SaaS distribution. The application’s source code is the same for all customers and when new features or functionalities are rolled out, they are rolled out to all customers. Organizations can integrate SaaS applications with other software using application programming interfaces (APIs). For example, a business can write its own software tools and use the SaaS provider’s APIs to integrate those tools with the SaaS offering. There are SaaS applications for fundamental business technologies such as email, sales management, customer relationship management (CRM), financial management, human resource management, billing and collaboration.

The biggest advantage of SaaS is that it removes the need for organizations to install and run applications on their own computers or in their own data centers. This eliminates the expense of hardware acquisition, provisioning and maintenance, as well as software licensing, installation and support. Other benefits of the SaaS model include:

• Flexible payments: Rather than purchasing software to install, or additional hardware to support it, customers subscribe to a SaaS offering. Generally, they pay for this service on a monthly basis using a pay-as-you-go model. Transitioning costs to a recurring operating expense allows many businesses to exercise better and more predictable budgeting. Users can also terminate SaaS offerings at any time to stop those recurring costs. It also reduces the burden on in-house IT staff.
• Scalable usage: Cloud services like SaaS offer high vertical scalability, which gives customers the option to access more or fewer services or features on demand.
• Accessibility and persistence: Since SaaS applications are delivered over the internet, users can access them from any internet-enabled device and location. As any SaaS application can run on a web browser it does not matter which operating system, such as Windows, Mac, Linux, Android or iOS, is used.