organization, and it may also use a SaaS HR public cloud application. In addition, to support its online commerce system, the company may leverage public commercial cloud services to ensure that customer service remains satisfactory during times of peak use, such as holidays. The same company might also create a private cloud application that it makes available to partners linking to its online sites. 

This type of hybrid environment will become the standard way companies run IT in the future. A company will typically use public cloud services such as SaaS to support customer relationship management, IaaS to add capacity on demand, and PaaS to support an experiment development process. This development makes sense because increasingly companies are looking for a cost-effective, flexible, and optimized environment to support internal operations, customers, partners, and suppliers. 

When a company selects this route, it takes the responsibility for the integration, security, manageability, and governance of the composite environment — including the public services that are included. 

In other words, IaaS and PaaS are foundational services that other cloud services will sit upon. IaaS itself is the foundation upon which PaaS can be utilized to build value. It supplies the infrastructure that developers can use to build applications. For example, many organizations are using IaaS and PaaS linked together for the development and operations process — which we will get into later in this book. These organizations may even be using IaaS and PaaS to build actual SaaS services. So, in some ways, IaaS services is the base of a pyramid with the infrastructure at the bottom, the middleware (PaaS) at the center, and the applications on top. 

