In BPMN, a Flow is a directional connector between elements in a Process, Collaboration, or Choreography.
There are two types of Flow used within BPMN. The first is a Sequence Flows which represents the sequence of Flow Objects in a Process or Choreography. The second type of flow is a Message Flow which represents the transmission of a Message between Collaboration Participants. The term Flow is often used to represent the overall progression of how a Process or Process segment would be performed.