See: Business Process Modeling Notation (BPMN), FTF Beta 1 for version 2.0. Page 293-305.

The conversation diagram has been introduced with BPMN 2.0 to provide a big picture of the interactions (in terms of related message exchanges) between collaborating participants.

The conversation diagram is similar to the collaboration diagram, but its pools are not allowed to contain a process and a choreography is not allowed between the pools.

The BPMN conversation diagram differentiates three basic elements.

They are described in the next chapters.