Difference between PostBPMNParseListeners and PreBPMNParseListeners

Hi Experts,

While reading about BPMNParseListeners, I noticed 2 different implementations using PostBPMNParseListeners and PreBPMNParseListeners, what is the difference between these two ?

Does this just indicate the sequence of execution of the listeners ? like triggering the listener before or after parsing the BPMN based on which ParseListener has been used.

Please advise.

Thanks