element vs nodal stress

In the options for the study, there is an option to analyzeeither nodal stresses or element stresses. If anyone knows thequestions to these:

1) What is the difference between the two?
2) When would you use element stresses instead of nodal stressesfor a study?
3) Can you site a real example of when you would switch it?

Thanks,
AVSolidworksSimulation