Flowable engine, BPMN

Am really new to this topics.I have one base doubt, Is that BPMN comes under flowable process or these are different.And also best IDE to use…

The flowable engine uses BPMN to do the execution.

As for an IDE. For the java part it is up to you to use the most convenient IDE for you. If you are asking about the modelling of the BPMN, then I would suggest the OSS flowable-modeler UI application