Swimlane objects (aka: Swimlanes) in BPMN are rectangular bins that represent members of a business process. A swimlane could includes movement objects which are done by that lane (participant), apart from black box that should have an empty body (we will speak about black box afterwards In this particular tutorial). https://caidennxdrh.blogofoto.com/54589512/how-much-you-need-to-expect-you-ll-pay-for-a-good-business-process-modeling-notation-example