Software as a service works through the cloud delivery model. A software provider will either host the application and related data using its own servers and databases or it may be an independent software vendor that contracts a cloud provider to host the application in the provider's data center. The application will be accessible to any device with a network connection. Software as a service applications are typically accessed via web browsers. As a result, companies using software as a service applications are not tasked with the setup and maintenance of the software. Users simply pay a subscription fee to gain access to the software. Software as a service is closely related to the application service provider and no-demand computing software delivery models where the provider hists the customers' software and delivers it to approved end users over the internet. In the software on-demand model, the provider gives customers network-based access to a single copy of an application that the provider created specifically for distribution. The applications source code is the same for all customers. When new features or functionalities are released, they are rolled out to all customers. Depending on the service level agreement, the customers' data for each model may be stored locally or in the cloud or both locally and in the cloud. Organizations can integrate these applications with other software using application programming interfaces. For example, a business can write its own software looks and use the software as a service provider's interface to integrate those tooks with the cloud offering. Software as a service applications and services typically use a multi-tenant approach, which means a single instance of the application will be running on the host servers, and that single instance will serve each subscribing customer or cloud tenant. The application will run on a single version and configuration across all customers or tenants. Though different subscribing customers will run on the same cloud instance with a common infrastructure and platform, the data from different customers will still be segregated. The typical multi-tenant architecture of these applications mean the cloud server provider can manage maintenance and updates more efficiently. It also helps in fixing the bugs faster. Rather than having to implement changes in multiple instances, engineers can make necessary changes for all customers by maintaining the one shared instance. Multi-tenancy also allows a greater pool of resources to be available to a larger group of people without compromising important cloud functions such as security and speed and privacy. Software as a service remove the need for organization to install and run applications on their own computers or in their own data centers. This eliminates the expense of hardware acquisition and provisioning and maintenance of it. It also eliminates the expenses on software licensing and their installation and support. Transitioning costs to recurring operating expense allows many businesses to exercise better and more predictable budgeting. Users can also terminate software as a service offerings at any time to stop those recurring costs. These services provide high vertical scalability, which gives customers the option to access more or fewer services or features on demands. Rather than purchasing new software, customers can rely on the provider to automatically perform updates and patch management. This further reduces the burden on staff.