You will most likely have to provide and manage the customer relationship management (CRM) application, the operating system, and the software development platform. An Infrastructure as a Service (IaaS) vendor provides computing and storage resources as well as the network infrastructure. The customer is responsible for everything else, including operating systems, software development platforms, database platforms, and software applications. With IaaS, the customer has a great deal of control and flexibility. However, IaaS places a larger management burden on the customer than the other cloud-based services do.

A Platform as a Service (PaaS) vendor provides the same services as an IaaS vendor does. In addition, a PaaS vendor also provides operating systems, software development platforms, and database platforms. PaaS is often used by companies that want to migrate their application development to a cloud-based solution.

However, a PaaS customer must use whatever software development platform is supported by the PaaS vendor, so a degree of control and flexibility is lost. The PaaS vendor is responsible for maintaining the operating systems, software development platforms, and database platforms, as well as any underlying hardware infrastructure. If you were to use a PaaS vendor, you would have to provide and manage only the CRM application.

A Software as a Service (SaaS) vendor typically provides a complete software application package to customers. For example, a company might contract with an SaaS vendor to provide hosted email services. The software application, the operating system on which the application runs, the hardware on which the operating system runs, and the network infrastructure on which the hardware communicates are maintained by the SaaS vendor, thereby lowering the management burden for the customer. Access to the software application is often provided through a web browser interface. If you were to use an SaaS vendor, you would not have to provide or manage anything; however, you would have to use whatever platforms and CRM applications that the SaaS vendor has available.