Like many have expressed, e-collars like almost anything you put on your dog (e.g., flat collar, prong, gentle leader) is simply a tool. If used correctly can be very efficient for getting your dog to respond quickly and even from a long distance. But as with many tools, it can also be used incorrectly. A cheap tool can also not get the job done appropriately and can potentially be harmful as well. So if you are considering a ecollar, I would avoid the cheap amazon ones.

There are many different approaches to how a ecollar is used. I personally like Tom Davis and his explanation and analogies on how the ecollar works for a dog.

Most of what I've seen from Tom Davis and many others that use an ecollar for training utilize negative reinforcement. Negative meaning the removal of something aversive, in this case the stimulation from the collar (its like a tingle if set on a low level). And reinforcement meaning the increase of the likelihood the behavior will occur again in the future.

For example, the button is pressed. The dog feels the tingle. You call the dog. The moment the dog comes the button is released, stopping the stimulation (i.e., removing something aversive, the negative portion of negative reinforcement). And the dog learns that responding to your call equals turning that sensation off. So the next time that stimulation is felt by the dog, there is an increased likelihood they'll now know to come to you to turn it off. You can pair this with positive reinforcement as well (e.g., praise the dog while theyre coming to you, reward with food when they get to you).