The batch widget are the command that will run on the scene. This widget are handled by an engine that make all the scene iteration work. You can configure the batch widget settings by clicking on the icon. Each batch widget will have your own settings values.
The system will run the batch widgets ordered by the stack sequence, so it is importante to make a logical sequence of execution on the Batch Widgets Stack area.
Batch Widgets Stack
If you want to know how to create you own batch widget, you can take a look at Creating a custom Batch Widget section.