The swimlane diagram is called a "swimlane" because each functional group or individual responsible for a particular activity is assigned to a specific lane, similar to a swim lane in a swimming pool. The diagram typically includes horizontal or vertical lanes, with each lane representing a specific department, team, or individual responsible for completing a specific set of activities.

Swimlane diagrams are often used to visualize and analyze complex processes and workflows, as they help to identify inefficiencies, bottlenecks, and areas for improvement. They can also be used to improve communication and collaboration between different functional groups or departments within an organization, as they provide a clear and concise representation of the process flow and each individual's responsibilities.