Book excerpt: A hybrid cloud is considered as the integration of multiple clouds that are aligned to the unique characteristics of different system types. IBM® defines a hybrid cloud as a secure cloud computing environment that uses services from two or more sources, such as a private cloud, public cloud, or traditional IT sources. A hybrid cloud transforms roles throughout the organization and allows business leaders and developers to innovate efficiently and faster. Applications that are built around a hybrid cloud infrastructure typically revolve around at least one of the following pillars of hybrid integration: API-centric applications Data-centric applications Event-centric applications This IBM Redbooks® Solution Guide describes Bluemix® integration services and how to use them to connect Bluemix applications to on-premise systems.