What is BPMN?
BPMN, short for Business Process Model and Notation, is a standard graphical notation for drawing business processes with events, tasks, gateways and flows, maintained by the Object Management Group.
In more detail
A rounded rectangle is a task, a diamond is a gateway where the path splits and a circle is an event such as 'invoice received.' Pools and lanes show which team owns each step. Version 2.0 added execution semantics, so a diagram can be run by a workflow engine as well as read by people, and ISO published it as ISO/IEC 19510 in 2013. Camunda and other engines execute BPMN directly. The notation is useful for mapping a process before automating it, even if you never run the diagram. Many small automations do not need it, and a whiteboard sketch with owners and decision rules often does the job. For complex or regulated processes, drawing the model exposes missing exception paths early.
Example
Drawing purchase-order approval in BPMN, a team finds that the 'amount over limit' gateway has exits nobody wrote down: urgent buys, split orders and repeat suppliers. Each becomes an explicit rule before any automation is built.