Question: About the five types of action of Node in jBPM

As we seen in follows, there are five types action for node in jBPM.

It's required to get clear every case.

   <node name="node1">
      <event type="node-enter">
         <action name="action1"></action>
      </event>
      <event type="node-leave">
         <action name="action1"></action>
      </event>
      <event type="before-signal">
         <action name="action1"></action>
      </event>
      <event type="after-signal">
         <action name="action1"></action>
      </event>
      <transition name="" to="end1"></transition>
  
      <action class="wby.NodeActionHandler"></action>
   </node>