7. Orchestration and Extension : 7.3 vCloud Messages : 7.3.3 Extension
   
7.3.3 Extension
An extension is a script or an application that has the following capabilities:
*Subscribe to an AMQP queue for receiving new messages.
*Triage the received messages.
*Process messages into operations (internal or external calls).
*Call the vCloud API to get more information on the objects involved in an operation and take action on blocked task.