flows. A Mule application begins processing a message it is received by an inbound endpoint in a flow. This flow can then either implement all processing stages, or route the message to other flows or subflows to perform specific tasks. Relative to the flow which triggered its execution, a flows and sub flows can process messages either synchronously or asynchronously Ref: https://developer.mulesoft.com/docs/display/current/Flows+and+Su bflows