Message Bus designs are leveraged to support complex processing for many organizations. This design provides a pluggable architecture that allows you to integrate applications into the main business processes, or improve scalability by attaching several instances of the application to the Message Bus. Variations on Message Bus pattern include:

• Enterprise Service Bus (ESB): Based on the designs, an ESB leverages services for communication between the bus and applications attached to this Message Bus. ESB provides services that transform messages from one format to another, allowing an applications that use incompatible message formats to communicate with one another.
• Cloud Service Bus (ISB): Similar to a Message Bus, but the main bus infrastructure is hosted in the cloud instead of in the company data center. A core methodology is the use of Uniform Resource Identifiers (URIs) and policies to control the routing mechanism through applications and services in the cloud.