## Introduction 

W elcome to Cloud Services For Dummies,  IBM Limited Edition . Whether public, private, or hybrid, cloud computing is becoming an increasingly integral part of many companies’ business and technology strategy. Cloud services help companies turn IT resources into a flexible, elastic, and self-service set of resources that they can more easily manage and scale to support changing business needs. 

While many different delivery models for cloud computing services exist, two foundational services are a requirement for making cloud computing into a strategic part of an overall computing infrastructure. These include Infrastructure as a Service (IaaS) and Platform as a Service (PaaS). IaaS is the services that enable you to gain access to compute and storage resources in an on demand model. PaaS is the services that sit on top of IaaS and enable you to build applications to support the business. 

No matter what your plan for your evolving IT infrastructure may be, you can take advantage of these services in combination with on-premises platforms to create flexibility for the business. Cloud computing serves different needs for different constituents within your organization. For business leaders, cloud computing is a cost-effective way to leverage IT resources to prototype and implement strategic change. For your IT organization, the cloud is a platform that allows it to be significantly more proactive and responsive when it comes to supporting strategic business imperatives. While IT is leading the charge in focusing on best practices that support the balanced use of public, private, and data center resources — the emerging world of hybrid computing — don’t lose sight of the fact that cloud is just as much about business model transformation as it is about technology transformation. In fact, many companies find that the cloud helps to support increased collaboration between business and IT leaders enabling them to more quickly adjust to changing market dynamics. 

