what is the difference of a dog with no bark collar that says shock or stimulus for the correction?

A bark collar that uses shock is only emits a small shock to the dog. One that uses stimulation or shake beep every time the dog barks. Either option works, but the choice depends on humans. Many believe that electronic collars are cruel, but are useful tools if used as a means of training and not a form punishment.

Mark Kaye is The Endorser – Pet Safe Electric Bark Collar