The theory behind traditional dog training was the belief that the best way to train a dog was to correct the dog when he was doing something wrong. If he was pulling on his leash, a painful jerk (while wearing a choke chain or pinch collar) was given to correct the behavior. If a dog jumped up on a person, the person was instructed to knee the dog in the chest. If there was a wet spot on the rug, the dog was roughly reprimanded, pushed down to the floor, and punished by having his nose rubbed in the wet spot. The idea was that if bad things happened, the behavior would disappear. This caused an undue amount of stress on both the dog and the pet owner.
Fortunately, in the early 1980's, positive reinforcement training became popular and pet owners learned how incredibly effective, easy and fun training this way could be! The dog was now rewarded for performing the right behaviors, which made him happy to repeat the good behavior. Positive training does not mean permissive. Positive trainers prefer to use "negative punishment"- taking away something the dogs wants - rather than "positive punishment" - adding an aversive the dog does not want. Positive trainers also believe in the generous use of management to stop the dog from practicing undesirable behaviors - in short, setting the dog up for success.