Software as a Service provides complete control of the service to the cloud provider. The cloud provider provisions, configures, and manages everything from infrastructure to the application. It includes the provisioning of infrastructure, deployment, and configuration of applications, and provides application access to the consumer. The consumer does not control and manage the application and can use and configure only parts of the application. They control only their data and configuration. Generally, multi-tenant applications are used by multiple consumers, such as Office 365 and Visual Studio Team Services, which are examples of SaaS.
Last few years have witnessed exponential growth in cloud adoption. While most of the initial growth was from small and medium enterprises, the current adoption is coming from large enterprises. This is happening primarily because of the following drivers mentioned:
- Cost effective: Cloud helps in eliminating capital expenditure and instead just incurs an operational cost. Users can stop purchasing physical hardware, expensive software's licenses and set up large data centers. All these are available on the cloud without user spending anything to buy them.
- Unlimited scale and capacity: Cloud provides the notion of unlimited availability of resources. This encourages organizations to deploy their workloads on it because they are not constrained by hardware availability limitations.
- Elasticity: Cloud computing is elastic in nature. Customers can shrink or increase their Cloud presence based on their needs easily using simple to use user interface. There is no upfront cost, resource availability constraints, and time lag in doing so.
- Pay as you go: Using cloud eliminates capital expenditure and organizations pay only for what they use, thereby providing maximum return on investment. Organizations do not need to build additional infrastructure to host their application for times of peak demand.
- Faster and better: Cloud provides ready-to-use applications and faster provisioning and deployment of environments. Moreover, organizations get better-managed services from their cloud provider with higher service-level agreements.