Software as a service, often abbreviated as SaaS, is an element of cloud computing. Software, specifically applications and their associated data, is hosted in the cloud and is then accessed by users with a web browser or a thin client. Our SaaS white paper offers a more detailed description:
Consistent with the basic notion of cloud computing, SaaS is a model whereby the customer organization licenses applications from a service provider and provisions them to its users as needed. The applications run on the service provider’s infrastructure and are accessed through a public-network connection. They may be made available through the Internet as browser-based applications, or they may be downloaded and synchronized with user devices.
SaaS applications are centrally managed and updated. Typically, they are highly standardized, although they may vary in configurability, efficiency and scalability. The most common pricing model is a subscription plan based on the number of users, but there may be additional fees for transactions, bandwidth, storage and processing time.
There are many similarities between SaaS and the services offered by application service providers (ASPs) popular a few years ago. But there are also stark differences, namely in terms of technology, operations and billing, multitenancy, pay-as-you-go pricing, and the ability to provision on demand.
Examples of SaaS include Salesforce and Microsoft Office 365.
What Is the Difference Between SaaS, PaaS and IaaS?
There are many “as a service” phrases floating around the technology community. Platform as a service, typically abbreviated as PaaS, is a more robust model of cloud computing, where users “rent hardware, operating systems, storage and network capacity over the Internet.” The benefits — scalability and flexibility — are consistent in all cloud models.
Infrastructure as a service, known as IaaS, is a foundational cloud solution. Users who are ready to move their entire server closet into the cloud might consider IaaS. Search Cloud Computing accurately describes some of the solutions provided by infrastructure as a service:
Infrastructure as a Service is a provision model in which an organization outsources the equipment used to support operations, including storage, hardware, servers and networking components. The service provider owns the equipment and is responsible for housing, running and maintaining it. The client typically pays on a per-use basis.
Characteristics and components of IaaS include:
- Utility computing service and billing model.
- Automation of administrative tasks.
- Dynamic scaling.
- Desktop virtualization.
- Policy-based services.
- Internet connectivity.
To learn more about cloud computing, download our free cloud-computing reference guide.